(at around 15 mins) When Homer and Bart are at Krusty Burger, while Krusty is filming his commercial, the pig runs to Homer in fear of being slaughtered. While Homer's looking down at the pig, Bart is shown to be wearing his regular blue shorts instead of the jeans that Flanders gave him.
(at around 46 mins) When Doctor Hibbert asks Mister Burns for power supply for the hospitals, Mister Burns writes it down using his right hand but it is an unchangeable tenet of the The Simpsons that Mister Burns is left-handed.
(at around 35 mins) When they flee the house and jump into the car, the house is on fire, even when Marge runs back into the house to save her and Homer's wedding video, it is on fire. When the townspeople carry the car to the backyard, the house is not on fire.
(at around 4 mins) At the start of the movie the church is shown set back from the street (as it is in The Simpsons), in later scenes (at around 27 mins) it is shown right by the road, next door to Moe's Tavern. On the DVD commentary, the film makers decided it would make more sense to have the church next to the bar since there is a scene where the alcoholics in the bar go pray and the worshipers of the church go drink. But they either forgot or were unable to go back and fix the other scene to make it consistent.
(at around 27 mins) When the dome is being lowered and the guy is thinking whether to stay in or leave, it seems about a foot thick at least. (at around 38 mins) However when Lisa and Colin place their hands on the opposite ends of the dome it seems only about an inch thick.
(at around 23 mins) When Homer dumps the "Pig Crap" silo into Springfield lake, he drives through a load of signs and the concrete fence. When he has dumped the silo and drives away the signs have all gone.
(at around 40 mins) In the Motel scene many times, you can see that the lock chain slot on the door doesn't have the circle where you put the chain through. It has it in a few shots but then in others it is a straight rectangle.
(at around 20 mins) In the assembly scene, Kent Brockman is seen in the first row, he is wearing a white t-shirt, but when the audience spits out the lake water that they drink, you can see Kent to the far left of the close up wearing a red coat.
(at around 48 mins) When the family move to Alaska, the door to their cabin opens to the left (looking at it from the inside) when Homer escapes from Bart and Lisa's "avalanche". But later in the film it opens to the right (from the inside).
(at around 48 mins) When Homer is buried by avalanches the second time and he comes out, his hair is ruffled, when the shot changes to Bart and Lisa, his hair is back to normal, this happens a couple of times.
(at around 29 mins) When Russ Cargill is speaking to the town of Springfield on the big screen, on the top left hand corner you can see the Simpson house with the dome turning on an angle cutting half way through the yard, but in other shots it is perfectly straight right at the back of the yard.
(at around 45 mins) When Marge and Bart are inside the gas station store while Homer puts gas in the pickup truck, Bart places a buzz cola on the counter next to the beef jerky. When Bart aims his sling-shot to shoot the hot dog off Homers' hand, the buzz cola is now near the tip jar. After he shoots the hot dog, the buzz cola is gone.
When Cargill is in the Oval Office, the portraits change. At first, the pictures are of Ronald Reagan and Maria Shriver. In the next shot, the portraits have been replaced by a mountain landscape scene.
(at around 21 mins) When Mayor Quimby calls Cletus over to check the barrier around Springfield Lake, you can briefly see that Cletus has nothing in his hands, then a second later, he's carrying a dead possum.
(at around 9 mins) When Lisa is visiting the neighborhood houses with the petition to stop dumping in Lake Springfield, she comes to Milhouse's house, his lawn is empty but in the next scene there is a large rock in the middle of his lawn.
(at around 5 mins) During the Church scene when Flanders is confessing to the immodest sense of pride; Chief Wiggum is clearly sitting behind Flanders. However, when Grandpa Simpson is doing his monologue of warning, Chief Wiggum seen on the other side of the church.
(at around 27 mins) At one point the church is shown next to Moe's, then later (at around 50 mins) when Barney and the others run out of the AA meeting it's shown with nothing next to it, near the edge of the dome.
(at around 1h 14 mins) When Russ Cargill is going to kill Homer, his clothes are torn up. The last time he is shown onscreen, his clothes were fine. There are no scenes of a previous fight or an animal attack before this. Perhaps he was right outside the dome when the bomb went off, and had less shielding from it than those inside.
When Grampa has his prophetic vision he is upright as he delivers the warnings 'Twisted tail, a thousand eyes, trapped forever!'. However later when Marge watches the footage of Grampa that Comic Book Guy took on his phone he says these words as he is writhing around on the floor.
(at around 29 mins) When Russ Cargill is talking to Springfield for the first time, he says that he trapped them like carrots. You see Moe standing next to Lenny and Carl, who then nod their heads at each other. 6 seconds later, Moe is standing alone at the back of the crowd.
After Lou shoots at Bart's skateboard, before Bart flies past the truck's windshield, when we see Krusty Burger across the street (note the post and triple window), the road surface has double solid yellow lines. The double lines can also be seen when Lou scrapes Bart off the window. However, when Bart is handcuffed to the post, that same road now has single broken lines. Also note when Lou cuffs Bart there aren't any lines at all on the road.
When Lisa sees Milhouse near the end, the door on his house hangs askew from the right door jamb and there is nothing above it. However, after Colin shows up, in the next shot when Lisa jumps up, the door now hangs askew from the left door jamb and there is wiring hanging above it (from the broken light fixture). Also note that the roof is much lower, and a spigot appears under the window. Additionally, Lisa's position when talking to Colin changes - first they're standing to the left of the house, then to the right of it, then in front of the stairs at the center.
When the Simpsons are trying to escape the angry mob, as Marge and Homer get into the car, the driver's side mirror is missing from the door. Then in the next shot, the side mirror appears on the door, but now the rear-view mirror has vanished.
When Homer falls onto the barbecue during the failed escape, there is a lower window at the corner of his house, which didn't exist in the exterior shot of the house, just before we see Homer and Marge watching the news about the silo being discovered.
At the gas station market, when Bart puts the can of soda pop on the counter, we see the yellow label on the glass beef jerky jar, facing away from Bart. When Marge points to the beef jerky its label has vanished, then when the clerk points to the similar looking family the label is back.
When Bart is inside the gas station market, while Homer pumps gas, Bart puts the soda pop can directly on the counter beside the white mat, but in the next shot, when Bart turns around the can has moved itself onto the mat, at the farther end.
When the Simpsons first get to the spherical cage at the carnival, the truck is parked with its front facing forward and its back end facing away, behind the ride. However, when Homer gets in and drives away, the truck has turned about 90°, with its back end now facing the ride perfectly.
At the carnival, when the Simpsons reach the spherical cage, the pick-up truck is parked right beside the base of the ride. In the shot of Homer's failed attempts at riding the motorcycle around the sphere the truck is gone, though it should be seen in this shot.
During Bart's flashback of him and Homer fishing, Homer drops the bug zapper into the lake. Dozens of fish come floating to the surface all over the lake. After the shot where Homer scoops up a fish and is zapped for it, there's a reverse-angle shot of Bart with no dead fish in the lake around him.
When Bart skateboards to Krusty Burger naked, he passes Agnes Skinner in the middle of town. On the left side of the screen is Mr. Largo, the school music teacher. A few shots later, when Bart approaches KB, Mr. Largo is seen walking down the sidewalk. There is no way he could have caught up and passed Bart in that time span. Not only that, but he and Bart are headed in completely different directions.
During Homer's attempt at rescuing his family, when the EPA truck stops at the fake stop sign in the wideshot the truck's visors are up and there's no rearview mirror, but in the next closeup both visors are down and a rearview mirror has appeared.
When Grandpa is freaking out in church, he says, "twisted tail" while kneeling with his hands cupped, "a thousand eyes" leaning up against a pew, and "trapped forever" standing up and spinning. On Comic Book Guy's cell phone video he says all of these on the floor rolling around. He's also saying it faster on the cell phone video.
When Homer kicks over the bomb, Comic Book Guy is seen seen behind him, with Carl, Cletus, and Krusty. In the next shot, Comic Book Guy is gone (appearing a few shots later at his comic book shop), and Barney is there instead.
When Marge is reconstructing Grampa's prophecy with magnets on the fridge, she moves the magnet saying" eyes" up a few inches to complete a sentence. When the shot changes to a wider angle, the magnet is back where it was before she moved it.
When Homer is forced into the house by Bart and Lisa's avalanche, it is broad daylight, but seconds later he is with Marge in the bedroom and it is dark outside. It is not snow surrounding the house, because the animals come in through the windows.
At the start when the Simpsons go to sit down in church, they enter the aisle in the order of Marge and Maggie, Bart, Lisa and Homer. When they sit down (instant cut) they are now seated Lisa, Maggie, Bart, Marge and Homer.
When the angry mob is outside the Simpsons' home, Lisa sees Colin in the crowd. Carl is next to him, with his torch in his left hand. In the next shot, when Carl sets fire to a bouquet Colin brought for Lisa, Carl's torch is now in his right hand.
When Homer shows up in the car as Bart is cuffed to the sign post, by the time Homer gives Bart the clothing the car moves up and back, and then when Homer kneels in front of Bart the car's back end is not visible, though it should be.
When Homer is grooming Spider Pig he is in Bart's room and it's on the end of the house because you can see the corner of the house, then he walks out of the room and goes in another room but that room is on the end of the house too, you can tell it's a different room by looking in the background so it doesn't make sense that both rooms are in the same place.
When Marge is in the kitchen trying to figure out the meaning of "a thousand eyes", behind Grampa there are three spoons hanging from hooks, but when Marge tells Homer that the warning in church was about the pig, the spoons have vanished and instead there are three cups hanging in their place.
After the mob knocks down the front door Krusty tells Teeny to, "Take out the baby," and when Maggie breaks her bottle to take on Teeny, the monkey is standing on the fallen door, but in the next closeup he's standing on the floor beside the door.
When Marge is in the kitchen with Grampa wondering what "a thousand eyes" can be, over the telephone there's a notepad with writing hanging from a clip, but when Homer walks in with the pig the notepad is hanging from a string and the writing has disappeared, but then it switches back again.
When Homer and Bart are on the roof attempting to fix the shingles, Homer's wearing a tool belt around his waist with assorted tools, but when Homer shakes the antenna his tool belt has vanished (Homer's belly cannot hide that tool belt), but it reappears when Bart's hanging onto the gutter.
When Homer runs into the EPA supply shed to find something to help him climb the dome, there's a window on each side of the doorway with little space between them, but in the interior shot not only is the style of window different, the space has increased significantly and the second window is gone.
During the scene with the angry mob, knobs on the bedroom's wall cabinets keep switching between being on the left or right sides of the cabinet doors (which would also change the direction those doors open).
While the Simpsons are walking the plank of wood between their house and Flanders' house, in the shot right after Plopper the pig pushes the wood plank off the windowsill, just as the Simpsons fall and the arrows fly by overhead, note the mysterious cable box and long cable that have suddenly appeared out of nowhere, attached to the wall beside the second window on the opposite side of the chimney.
During the town hall meeting, on the lower floor there are two sections of seating divided by an aisle, and in every shot of the audience we see people switch seats or sections they're in, and some clothing changes as well. Just a few examples: 1) the Sea Captain's first seated behind Moe and Lenny, then he's behind Willie; 2) Krusty, Mel, and Luigi are behind Bumblebee, but the next closeup has Mel seated in front of Luigi and Bumblebee, and Krusty has vanished, but he reappears when they spit the water; 3) And in that same shot the guy behind Luigi is wearing a white jacket and purple shirt, but when they all gasp he's wearing a black shirt and green jacket. And so on.
When Homer and Bart are on the motorcycle trying to get rid of the bomb, the bomb slips out of Bart's grip. When he's hanging onto his father's shirt, Bart first grips the bomb's handle with his palm and fingers facing the front of the bomb, with the clock. Then when he's hanging onto his father's hair, Bart's hand has flipped around and he's now gripping the bomb's handle with his palm and fingers facing the back of the bomb. Something to look out for is the shot just before the close-up of Chief Wiggum, because as Bart raises his arm the bomb actually flips over in his hand while we're watching. Quite impossible.
When Marge and Homer are in the backyard with the silo, there is a drawing of a pig on it, but in Homer's close-up with part of the silo in the background, the part of the silo that's visible should have the pig drawing at the top, but it does not. Later, when the silo's found in the lake, the words and drawing differ and are much lower on the silo.
When Homer circles the dome on the bike, in the first two shots (close-up and wideshot) Homer's left hand is gripping Bart's left wrist, but in all of the following shots it is Homer's right hand that is gripping Bart's left wrist.
When Russ Cargill spreads the five unthinkable options on the President's desk, the book's spines are all facing to the left, but after the President chooses option three, in the close-up the spines are facing to the right.
When Abe goes nuts in church, Comic Book Guy gets his phone to record him. When it cuts to Abe, Comic Book Guy is not holding his cellphone. However when the family roll Abe out of the church, Comic Book Guy is holding his phone again.
When President Schwarzenegger tells Russ Cargill he will have to go back to making family movies, there is a "Diaper Genie" promo poster on the Oval Office wall and on the immediate left of President Schwarzenegger's desk. But the promo poster disappears and the walls of the Oval Office become further from the desk in the next long shots.
When the family move to Alaska, the door to their cabin opens to the left (looking at it from the inside) when Homer escapes from Bart and Lisa's "avalanche". But later in the film it opens to the right (from the inside).
In the scene where everyone is climbing the rope to get on the top of the dome, Homer should already be at the top, but when the camera points to the top of the dome, he does not appear there. The next scene shows him back at the top of the dome again.
When Maggie does her disappearing act through the sinkhole, and Marge rushes to get Homer, the wooden porch swing is directly in front of the window, with its top beam as high as the top of the window. When Homer says, "This dome can play tricks on you," note the door and window behind Marge, because the swing is now gone.
The second time Russ Cargill spreads out the five options on the President's desk, the name bar with 'President Schwarzenegger' (yes, you read that right) on it vanishes and reappears on the desk twice.
When Russ Cargill appears on the big screen to explain the dome to Springfield, Moe is standing next to Homer and Lisa. A few shots later, Moe is standing next to Lenny and Carl, with different people around him.
In the cinema, when Homer tells everyone how boring this is, behind Bart, Lisa, Maggie and Marge sits Otto, Kirk van Houten and Barny, but in the next shot behind them sit Otto, Jasper, Kirk van Houten and Moleman.
When Bart is having target practice on Homer, who is carrying bricks, the timer lying on the grass goes off. When Homer walks over to Bart to give him the dare, the timer is gone, though it should be visible.
When a naked Bart is cuffed to the sign post, beyond the grass behind him is concrete walkway then the curb. Then when Homer steps out of the car, the grass goes right up to the curb's edge, but when Bart asks about pants, the walkway is back again between the grass and curb.
In front of Krusty Burger, when Lou carries a naked Bart to the sign post, the post is embedded directly in the concrete walkway slab, just beside the left corner of the patch of grass. Once Bart is cuffed, the sign post has actually moved down about 4 feet, and is also now embedded directly in the grass at the right corner. In following shots, it's at the left corner of the grass and then right again.
When Marge looks at the magnetic words "a thousand eyes" on the fridge and asks Grampa about it, other than the highchair Maggie's sitting in, there are two chairs around the kitchen table - one Grampa's sitting on and one empty chair, but in the next shot as Homer introduces the newest Simpson there are now three chairs - Grampa's chair and two empties, the one beside Marge appeared out of nowhere.
When Chief Wiggum orders his men to open fire on the dome, and the bullets ricochet back, the officer standing farthest from Wiggum is wearing blue gloves on both hands in the overhead side shot, and the other officers are not wearing gloves. However, in the shot facing them, the officer kneeling farthest from Wiggum is the one wearing blue gloves, and now all the others are barehanded.
We see the interior of Homer's car twice, first when Homer is at the Hazardous Waste Treatment Center, and then again when he and Marge are trying to escape the angry mob. The dashboard and steering column are entirely different both times.
When the angry mob breaks down the front door of the house, the door knob is on the right side of the fallen door, at Chief Wiggum's feet. However, when Maggie breaks her bottle and thrusts it forward, in the next shot as Mr. Teeny turns and runs away, the doorknob is on the left side of the door, at Bumblebee Man's feet.
After Homer nailed the bedroom door shut and then mimicked the sound of a chainsaw, when the hands of the angry mob push through the holes again, we see Marge and Lisa sitting at the edge of the bed where the bed's tall footboard should be. The footboard is back when Spider Pig pushes the plank off the windowsill.
After Homer and Marge watch the news about the silo found in the lake, when Homer walks to the window we see that there are two blue panel drapes with tiebacks on the left and right side of the sliding window. However, when Homer shouts at the mob in the exterior shot, there is also another blue panel hanging down at the center of the sliding window, and the side panels are hanging straight down, without the two tiebacks.
After the news broadcast about the silo being discovered in the lake, in the first shot of Homer nailing the bedroom door shut, the blue panel drapes and valance have become beige (seen right behind Lisa and Bart).
When Marge and Homer are watching the news about the silo found in the lake, the TV sits on the dresser in front of their bed. The TV has vanished when Lisa runs into the bedroom, and when Marge tells Homer to go out, face the mob and apologize for what he did, the rest of the wall is visible, sans TV.
When the silo has been dumped and the pollutant begins spreading, there is no rope on the ground behind the car, but when Homer gets back into the car to drive away, there is a bunch of rope lying on the ground behind the car.
After Bart has caused the avalanche in Alaska, the animals help Marge and Homer have a special moment, and when the couple join hands note the large window beside the TV, which just vanishes in the following shots of that bedroom.
When Homer drives toward the small Alaskan booth, on the road there is a single line of broken yellow lines leading to the booth, but when Homer hugs the booth guy the road is visible and there are double lines consisting of a solid line and broken lines.
When Homer is driving toward the small Alaskan booth, right beside the booth there is a tall flagpole with two raised flags, but when they leave the flagpole has vanished, though it should be seen in this shot since it's on the same little 'island' as the booth. Also note that the snow on the booth and island has vanished.
When Bart walks into Krusty Burger, in the overhead shot the trash receptacle that's beside the door has a plain, flat top with nothing atop it. However, in the following shots the top of that trash receptacle has changed, it now has two raised side lips, and there are also two trays on it. Its height compared to the window behind it drastically changes as well.
When Bart walks into Krusty Burger, in the overhead shot we see Ned and his sons sitting on stools with bases attached to the floor. In the next close-up, Rod and Todd Flanders' stools are in different positions - note the checkered floor.
In the exterior shot of the Simpson house, before showing Homer and Marge watching the news about the silo being found in the lake, we see the side window (facing the Flanders' house, from which they escape later) is a horizontal sliding window. However, from inside the bedroom and also when they are escaping, that same window has changed to a vertical sliding window. The same thing happens with the other window on the opposite side of their chimney.
Right before Homer yells out of his bedroom window, when the shot moves forward, passing through the large angry mob, we see the mob walking down the street which is perpendicular to the front of the Simpson house (not the street in front, that runs parallel to his house). The problem is that after the dome was placed, when Homer screamed in the backyard, there was an overhead shot that zoomed out and we saw there are homes across the street from his house, no perpendicular street.
After the dome is placed, when the Simpson family runs out the back door of the house and Homer shouts, there is only one window on the second floor, above the back door. There should be two windows. The light fixture on the wall beside the door is also gone in some shots.
When Marge brings Homer to see Maggie outside the dome, but she's not there, he soon starts cheering and in the dome's reflection he raises his right arm which means it's his left arm that is actually raised, but when it cuts to Marge and Homer (in the view from outside the dome) it's his right arm that's raised in a cheer.
When Marge sits on the back porch swing knitting 'dome sweet dome' and sees Maggie outside the dome, she runs inside to get Homer. The back door is right behind her and it's a solid door, with the round window missing, though the window does reappear.
After the book knocks over the AA meeting's coffee machine, when the group of people run out of the church, the ground in front of its doors is flat and leads straight to the walkway. Additionally, there is a second large area of grass between the sidewalk and the street, and the large cross at the front is gone. However, in previous and following shots there are stairs at the front of the church, and the area of grass only between the church and sidewalk/street.
With the second set of options spread across the desk, when Cargill starts manipulating the President's option choice, there is a blank wall to the President's left (the wall faces the viewers). Also note that in this shot the table behind the President (with framed photos) is gone. When Cargill walks away from the President holding 'option 4', that blank wall now has a built-in bookcase, a table and chair.
When Homer puts the video in the VCR player, as Marge says "Homer", outside the window shows a dark sky in the background. Marge then talks for a bit and the shot returns to Homer saying "Way back." Outside the window suddenly shows a background that is partially brighter and raining.
After the Alcoholics Anonymous meeting runs out of the dome, Barney starts yelling and a huge crowd is visible behind him. Bumblebee Man is standing a few meters away from Barney on the end of a row. Next shot, Otto and Moe have suddenly appeared next to him as well as a huge crowd.
When the Alcoholics Anonymous run out of the church, Barney yells out "I can't take another minute in this dome!" and charges towards the dome. In the overview shot, the church is directly behind Barney. In the following shot that shows Barney hitting the dome, the background has changed completely. The church is no longer there and two houses have suddenly appeared.
When the two deer enter through the cabin window to help Homer and Marge, a trail of snow is visible behind them and in front of the window. In an instant close-up of the smaller deer, half of the snow has instantly melted and vanished. Then all the water has vanished and it's just snow. Then a few shots later, the snow vanishes completely.
When Marge and Bart are at the counter at the gas station, the first shot of them at the counter shows the strap on Marge's bag facing behind the bag. The shot then changes to Bart using his slingshot, and Marge, visible in frame throughout the entire shot, is never shown touching the bag, but when the shot cuts again, the strap is suddenly in front of the bag.
When the Simpsons are at the gas station, Marge congratulates Bart on being sober for 24 hours. The Buzz Cola can next to Bart has the logo facing front ways. Bart then aims his slingshot which cuts to a shot from behind them and the Buzz Cola logo on the can is still facing front ways, despite the angle change.
When the mob are invading, Lisa sees Colin in the crowd with a bouquet of flowers and nothing else. Later on after the house is destroyed, he suddenly has a guitar with him despite not having it with him a few minutes earlier.
When Maggie gets out the dome, Marge runs to get Homer. They run outside in a straight 12 o'clock direction. Yet as Homer says "This dome can play tricks on you", they are suddenly several steps to the right of the door instead of being directly behind it.
When the mob approaches Homer's house, it is undamaged. However, a few seconds later when everyone is out of the house, it is suddenly ablaze, and it is clear that it's falling apart. But when the sink hole sucks the house in a few minutes later it is undamaged, and no evidence of a fire is visible.
When the dome is being placed over the town, the church and Moe's are right next to each other. But when Barney runs out the church at the Alcoholics Anonymous meeting later in the film, Moe's is nowhere to be seen.
When everyone approaches the edge of the dome, a group of police officers arrive. As Chief Wiggum says "open fire", he is standing in front of the officers. In the next shot, Wiggum and the officers are standing even with each other.
When Bart and Ned find the mutated squirrel, two EPA workers find the creature. When the female worker says "Environmental Protection Agency" after Ned asks who they are, the squirrel is standing on a rock with nothing under it. In the next shot, there is suddenly something under it for the EPA worker to contain it with.
After Homer decides to bring Spider-Pig home with him, the scene cuts to Maggie playing the game "Baby Blast." On the back of the game console is the disc with the words "Baby Blast" written on it. As Grandpa says "I'm pretty sure a thousand is a number" a few seconds later, the words "Baby Blast" have vanished from the disc.
When they film Krusty's advert in Krusty Burger, "Action" is said by the director and the only things shown are Krusty, the pig and the table the pig is standing on. Krusty then starts talking whilst filming and picks up the burger known as The Clogger. This burger was never visible during the previous shot as the director said "action".
At Krusty Burger, a shot is shown from inside Homer's mouth eating a burger. The shot cuts to outside Homer's mouth where he takes another bite. He removes the burger from his mouth and it is the exact same size as it was from before he took the bite.
When Nelson yells out "Say global warming is a myth!", Milhouse covers his face and says "It's a myth, further study is needed." Right at the end of the shot, he clenches his eyes shut. Instant shot following, his eyes are open.
After the Simpsons have left the church with Grandpa wrapped in the rug. Homer asks "Who wants waffles?" In this shot, there is a line along the left side of the rug, showing us where the end of the rug is located. A few shots later, as Homer says "I rest my case", the line showing us the edge of the rug has vanished.
During Grandpa's freak out in church, as he says "Trapped forever", behind Kirk van Houten is Chief Wiggum. In the next shot, Professor Frink has suddenly appeared behind Kirk, and Chief Wiggum is suddenly behind Frink.
At the end when everyone is cheering at Homer and Homer notices Marge, Lenny and Carl are in three places at once. First, just as Homer starts his bike to get Marge, Lenny and Carl are right behind him. Second, just after Homer carries Marge on to the motorbike Lenny and Carl are behind Homer without enough time to move. Third, just as Homer and Marge drive off in the motorbike, Lenny and Carl are now in front of Homer without enough time to move.
Cletus is shown on a roof attempting to distract Cargill as the group was trying to climb the rope, and is still there when Cargill turns off the transmission between Springfield and Cargill. Yet when Homer says "I can't do anything right" a few minutes, Cletus is suddenly shown in the background behind Homer.
When Bart falls off the roof and grabs hold of the gutter, in the overhead shot the gutter is an L-shape with a 90° angle, but after Homer and Bart high-five each other, the gutter is a straight line that ends at the corner.
When Homer dumps the silo in the lake, there are the words "Pig Crap" on the front and there is no writing on the back. However, when Lou and Eddie find the silo later in the movie, the "Pig Crap" words are there, but the words saying "Return To Homer Simpson, No Reward" has appeared out of nowhere.
When Homer leaves the bar Eski-Moes (in Alaska), he catches hold of a truck, which propels him up the hill in front of his cabin. However, he runs outside a few minutes later and floats away on the heart-shaped iceberg, which has suddenly appeared on a lake that was never there before. The road that the truck was on earlier is gone.
The Simpsons enter a motel (Red Rash Inn) to hide, and it's clear from the outside that the building is only one story high. But when Homer flings back the curtains to reveal the buildings and billboards, it appears that the motel room is located on a much higher floor, since the view seems to be level with the building tops.
This is when Homer is about to conquer the 'Ball of Death', on his third attempt. As he is going up, just after Lisa shouts, "Don't slow down, speed up," when Homer has his fingers on the brakes, the Ball of Death suddenly gets a lot bigger.
In the wide overhead shots as the crowd starts gathering at the dome edge and when Russ Cargill's image appears, note the homes on the third block at the far left side of the screen, which change when Cargill says, "Believe me it's the last thing we wanted to do."
When the Simpsons enter church they walk past Dr. Hibbert and he's wearing a solid black tie, but when Grampa has the outburst Dr. Hibbert is wearing a striped red tie. (Also, the stripes at the tie's knot are the same direction as the tie blade, though when tying the knot the stripes would be going the opposite direction).
In the first interior shot of the church, there are nine rows of pews on each side of the aisle, with Mr. Burns in the last pew on one side and Mrs. Glick in the last pew on the other side, but when Grampa starts rolling around on the floor there are eleven rows of pews, with two extra pews on both sides behind Burns and Glick. Additionally, the Reverend's wife is seated in the first pew, but just as Grampa shouts, "Trapped forever," we can see the back of an extra pew in front of Helen. (The front of the raised pulpit has vertical wood panels, and the pew is solid).
At church, seated in the pew behind the Simpsons are Moe and Kirk, and in the pew behind Moe and Kirk are Disco Stu, Professor Frink, and six other people, but just as Grampa shouts, "Trapped forever," in this one shot that entire pew with Disco Stu, the Professor, and all the other people has vanished, but then the pew reappears.
While Bart watches from the tree, Homer brushes the pig's hair and carries the animal out of the room, then Bart turns to see Ned tucking his kids in bed, and when Bart turns toward Homer again the lower window has a center muntin bar, but when Bart aims his slingshot at Homer that muntin bar has vanished.
Russ Cargill puts the 5 options on the desk the first time and spreads them out. His hand is then covering the number 5. Camera changes to another angle and his hand is no longer covering the number 5.
When the dome is lowered we see Sideshow Mel hitting it with his bone. In the background you can see Dr. Hibbert and his wife. When Russ comes on the dome, Dr Hibbert and his wife are now in a completely different spot, and have changed sides.
When Krusty is filming the advert for the Clogger, before the director says action the bin is to the side of the set with a boom mic stand right next to it. After the advert, the boom stand has gone as seen when Krusty throws the burger away.
At the town hall meeting, when Lenny says, "It's not so bad," there's a single head light fixture on the wall near the balcony, but when Moe shouts, "This is why we should hate kids," there's a double head fixture on the wall, and yet in the first overhead shot of the meeting there's no fixture at all in that space.
After Scratchy blows up in the movie they're watching, when Homer stands up in the shot facing the audience there are two empty seats behind Homer, between Dr. Hibbert and Marge, who's seated beside Lisa, but in the next shot facing the screen Marge is now seated beside Dr. Hibbert, and there's only one empty seat now between Marge and Lisa.
While Bart's standing on the roof's TV antenna when Homer's shaking it, in the overhead shot of the house - note the front walkway and the wood fence between Flanders' and Simpsons' houses, the chimney is actually missing from the side of the roof adjacent to Flanders' house, and the antenna is also much closer to that side of the house than it should be.
There's a tiled patio at the back of the house with a total of twelve large tiles, but when the house goes down the sinkhole there are sixteen tiles in total. Plus the fact that when Bart's on the roof hanging from the gutter the tiles below are white (they also appear white when the house falls into the sinkhole), but when the dome is placed over Springfield the tiles are brownish-orange.
When Marge gets into the car and tucks the wedding video into her hair, the rearview mirror is attached to the roof of the car, but as the mob carries the car to the backyard the rearview mirror is now attached to the windshield.
There's a water spigot under the window on the wall at the front of the house, near the garage door, which can be seen after the lake is blocked off, but this spigot didn't exist right before Bart skateboarded naked, then it vanishes again and reappears during the fire.
When Cletus goes to distract Cargill, a crowd of Springfield citizens go to place the KBBL news tower next to the rope so they can climb up it. They are all on the ground when Cletus starts talking to him. Cletus then says "Look what I can do with my thumb" and the crowd is suddenly half way up the rope with no time to do so.
Marge and Bart discover the wanted poster of them at the gas station. When the clerk enters the scene, his shadow is cast on the wall, cork board and the wanted poster behind him. The clerk never moves, nor does the lighting ever change, but as he says "OK" after Marge asks for diapers, his shadow has vanished.
After Marge shouts into the megaphone for the bomb to be thrown, it cuts to Homer and Bart while they're riding sideways on the motorcycle, and the bomb's under Bart's left arm while he's holding onto Homer with his right hand, but in the following shots the bomb's under Bart's right arm while he's holding Homer with his left hand.
When Marge and Homer are watching the news about the silo being found, the '6' on Kent Brockman's microphone keeps getting smaller, the color of his belt buckle changes and the landscape in the background changes.
While Marge and Homer are watching the news on TV note their bed's footboard, then when Lisa angrily rushes into her parents' bedroom to confront Homer, the footboard's style is entirely different, but when Marge pulls Lisa away from Homer the footboard changes back to the original style.
When naked Bart skateboards past Wiggum's squad car, the vehicle does not have a partition screen between the front and back seats, a rear-view mirror, or a side mount searchlight, but in the following shots all have suddenly appeared, with other changes.
During the church scene, Martha Quimby is wearing an outfit with sleeves, but soon she's sleeveless, then back to sleeves, and finally sleeveless again. Behind Martha sits Bernice Hibbert, whose pearls also disappear and reappear.
There is a blue Presidential flag behind the President, with windows on both sides of that blue flag, but after viewing the security camera footage of domed Springfield, the window on the far end has become a solid wall. That window returns when Cargill influences the President's choice of options.
When Russ Cargill spreads the second set of the five options across the President's desk, the Oval Office background is actually backwards - note the ship painting over the fireplace and pictures on the wall. The background keeps flipping between being backwards and the correct way until 'option 4' is chosen.
When Russ Cargill provides the President with the first set of five options and spreads them across the desk, the handle on the mutated squirrel tank is perpendicular to the president, but in the next shot the handle has flipped around and is now parallel to the president.
After Russ Cargill goes through the eye security system, in the overhead shot as he enters the Oval Office, we see the Seal of the President (on the rug) centered between the two couches, and there are two red chairs behind each of the couches. However, when Cargill holds up the tank with the mutated squirrel, the large round Seal is off to the side of the couches and one of the chairs is gone from behind the couch.
When Russ Cargill holds up the tank with the mutated squirrel to the eye security system on the wall, there is a square piece under the handle to secure it to the top. However, when Cargill holds the tank up to the President that square has vanished and it's just the handle. Then when the President is face-to-face with it, a bar has appeared between the two sides of the handle.
When Lou shoots at the skateboard Bart goes flying in the air, and in the next shot (before he flies past the truck's windshield) we see Krusty Burger across the street (note the triple window and post), and there is a tall, long bush between the street and Krusty Burger. That bush vanishes in the following shots.
When Lou scrapes Bart off Krusty Burger's triple window, Lou is pushing Bart forward in front of him, so Bart should have fallen on the ground somewhere to the front/side of Lou. However, in the next shot Bart is lying on the ground about 20-30 ft behind where Lou had been standing, on the grass that's in front of the door.
When Lisa goes door-to-door with the petition, the door on Milhouse's house has two grooved panels, a tall, 12-panel window, a light fixture above the door, and there's a tree between it and the blue house next door. When Lisa sees Colin and Milhouse again near the end, some of the features of the house have changed - unrelated to the damage Springfield's homes have suffered. The door now has three grooved panels and no mail slot, the window is much shorter, and the light fixture above the door is gone, with no hole in the wall if it had been broken off. The tree between the house and the blue house next door has changed position on the grass as well.
When Nelson punches Milhouse in the stomach, there is a hose hanging below the window attached to a spigot, and the front door has two grooved panels on it, but when the dome approaches and Milhouse swallows his inhaler, the door is flat and smooth, and the hose, its holder and spigot have vanished and been replaced with a bush.
When Lisa is going door-to-door with the petition, Milhouse opens his front door and there is no mail slot on the door, but when Nelson punches Milhouse in the stomach there's a mail slot on the door, beside the door knob.
After Homer taunts the angry mob about not knowing where he lives, the mob gathers in front of his house, and in the shot of Homer and Marge in the bedroom note the light switch on the wall and the items on the dressing table, but in the next shot as Lisa and Bart run into the room the items on the table have vanished and the light switch is gone.
While Marge and Bart are in the service station market, when Marge points to the beef jerky jars the end of the service counter is right beside the jars, but when the clerk fills the bag the counter is now much longer, past the cigar display.
After being held in the EPA truck, when Marge and the kids wake up at the Town Square - the remains of the courthouse with its lion statues are behind them. The buildings to the left of the courthouse change in following shots, such as while Cletus distracts Cargill, or when Homer's on the motorcycle and grabs the cowboy hat.
After Russ Cargill places the tank with the mutated squirrel on the President's desk, when Cargill says, "Here's our chance to kick some ass for mother earth," the tank's not on the desk where it was placed, but then it reappears where it should be.
When Homer walks into the kitchen to show Marge his new Simpson addition, we can see the shelving unit under the window in the den that has a single spindle and finial from the top to middle shelf, with two blue books lying on their sides, but in the closeup of the pig's tail now there are two spindles and two finials, with a red book that's upright.
When Homer brings his pet pig home to meet Marge, they enter the kitchen and the roll of paper towels is hanging under the cabinet near the window, but in the closeup when he and the pig share a carrot the paper towel roll and its holder have both vanished, and then they reappear. A cutting board suddenly appears on the counter as well.
(at around 1h 3 mins) When Homer is riding the wrecking ball, he first bumps into a giant metal statue then into a fork on a bill board. However, in the next shot, he is bouncing between the rock and the "Hard Place" and neither the statue nor the fork are visible.
(at around 57 mins) The face masks in the medicine woman's shelter and the totem poles are not part of Inuit culture. They belong to the Haida Indian tribe who reside much further South down the British Columbia West Coast and the South East area of Alaska in the temperate rain forests.
(at around 56 mins) Marge, Bart, Lisa and Maggie Simpson take a passenger train from Alaska to Seattle, WA. (The exact same train seen in Alaska is shown arriving in Seattle). There is no railroad link between Alaska and any other US state.
(at around 36 mins) When the Simpsons are in Bart's tree house and it is being pulled down by a school bus, we see Grampa Simpson take aim at them with a shotgun that obviously has two barrels, but he cocks it by pumping it. A double barreled shotgun is cocked by pulling the hammer back.
Though Arnold Schwarzenegger is shown being the President of the United States, in actuality he wouldn't be eligible to hold the office, as the US Constitution requires the president to be a natural-born citizen.
(at around 23 mins) Hans Moleman is present when Homer dumps the silo in the lake, but nobody finds out it was Homer until the silo is discovered. But Hans doesn't have good eyesight and isn't very quick on the uptake. There is also a The Simpsons running gag where in several episodes Hans disappears and is presumed dead, only to turn up alive in a later episode, so this could be his disappearance for the course of the movie.
When Homer goes to the fair, he uses the last $10 that the family has to win a truck. In the next scene at a gas station, Homer is filling up gas, and Marge is planning to purchase beef jerky. However, they could have obtained more cash in between scenes.
As the Simpsons probably didn't have their passports, they shouldn't have been able to cross the border to Canada, and again when they reached Alaska. Even if they had they would have been caught and arrested because they were fugitives.
When Lenny calls Homer about free doughnuts Hans Moleman is in the background (in Lenny's scene) then Homer drives to the lake to dump the pig crap silo and he runs over Hans Moleman, But he was at the doughnut shop so he couldn't have gotten to the lake in time.
There are two cars driving behind the EPA truck containing Marge, Bart, Lisa and Maggie. But when Homer uses the bulldozer to try and break the family out the truck, the two cars behind the truck don't even realize for some strange reason that a bulldozer is trying to destroy the truck. There's no way they couldn't have not seen the bulldozer since they were just behind it.
(at around 31 mins) When Homer and Marge go out and look for Maggie, Homer sees his reflection and thinks he's outside of the dome. Yet, Marge's reflection is not seen, even though Homer runs around her.
(at around 19 mins) When Moe dumps the truckload of empty beer bottles into Lake Springfield, look closely at Moe in the truck. As his head turns away, there is no animation of his head turning and it simply "jumps" to him looking forward.
(at around 35 mins) When Marge went back to get one item from their burning house, she took their wedding tape. Homer and Marge had no wedding; they got married in a wedding chapel across the state line.
When Grandpa is being rolled out of the church, everyone is looking at him. As this happens, look closely at the Squeaky Voiced Teen sitting next to Hans Moleman on the right hand side of the church. As he turns his head around you'll see his eyes disappear as he stops turning his head.
After the crowd boos at Homer after kicking the bomb, Bart is shown walking past The Android's Dungeon and the shot pans over to show Comic Book Guy. Just as the shot begins to pan over, it can be seen that Comic Book Guy randomly pops up on screen.
When Homer drives through the barrier the second time (leaving the lake after dumping the silo) pay very close attention, his car smashes one portion of the barrier, but his car passes through a second portion of the barrier without breaking it.
The goof items below may give away important plot points.
(at around 1h 8 mins) Just as Homer reaches the top of the dome, the next shot looks up showing the people climbing up on the rope to the hole. You see the top of the dome and the hole, but Homer is nowhere to be seen.
(at around 1h 7 mins) When Homer is first seen climbing the dome with super glue on his hands the camera pulls out to show virtually the entire dome, yet there is no sign of the helicopter dangling the bomb through the hole, although a subsequent shot shows it only a few feet above the top of the dome. Nor is there any sign of the bomb itself or the rope that supports it.
(at around 1h 14 mins) Towards the end, Bart and Homer are about to be shot by Russ Cargill, who has a double barreled shotgun, but when he cocks it, we only see one hammer. A double barreled shotgun has two.
(at around 1h 13 mins) While riding a motorcycle around a ball can be done by generating centripetal force, it's physically impossible to ride the motorcycle up to the top of the dome the way homer did.
(at around 57 mins) The medicine woman and Homer don't introduce themselves - since Homer is unconscious when we first see her - yet when she attempts to revive him she calls out his full name. But Homer was probably carrying his driver's license which she read.
(at around 1h 2 mins) When Bart, Lisa, Marge and Maggie are prisoners in the back of the EPA's van, Lisa is playing her saxophone, which she did not take with her when they fled from Springfield to Alaska.