(at around 18 mins) Jacob cuts Peaches face with a glass shard to escape after she attacks him. In the next shot, the cut is gone.
(at around 1h 19 mins) When Andrea pulls the doorknob off, black slime pours out over her hand. In the next shot, her hand is completely clean.
(at around 1h 13 mins) When Dr. Stafford is taking a bath and the sludge starts to come out the faucet he runs his hands through his hair getting sludge in it and on his face, in the next shot the sludge is suddenly gone...That is because the slime is supernatural, like the slime that Andrea found in her bed, which also disappeared.
(at around 46 mins) The yogurt lid disappears and reappears between shots when Leonard is in the kitchen.
When Rusty and Iris are playing chess, Iris takes Rusty's queen with her rook, and announces "Mate" to signify Rusty's king will be taken on the next move to end the game. However, from the position shown, Rusty could move his king forward-right to the square next to his pawn, or simply take the attacking rook with his rook, and the game would continue. This may be simply an error in dialogue, as what is shown is a check, which is used to signify a threat to the king but still leaves a way to avoid check-mate, which means the king cannot escape being taken next move.
When the living room doors slam on Lisa, if you look closely, there are wires attached to the knobs.
(at around 46 mins) When Dr. Stafford is in the kitchen and time begins to slow down and stop, the timer on the microwave stops but there is a flashing indicator still blinking on and off in the lower right part of the microwaves display.
When Iris is being loaded into the ambulance, she blinks, but she's already dead.
A microphone can be seen dangling above the characters several times in the film. First, in the scene down in the kitchen before Rusty and Lisa leave for school and before Jacob goes jogging (at around 15 mins). Again in the hospital while the doctor greets Andrea (at around 18 mins), when Andrea is introducing Leonard to Jacob (at around 39 mins), when Lisa and Andrea are in the living room talking (at around 55 mins), and at the end of the movie when Andrea is leaving the house.