When Maggie is describing Bob's proposal, she refers to being at an "Oriole" game. When people use the actual name of Baltimore's Major League Baseball team, they always refer to the "Orioles." (The team's nicknames are the "O's" or the "Birds.")
Maggie presents Ike with a gift of the 'Miles Davis' album "Kind of Blue." The closeup shot is that of the original 1950's album cover. The camera cuts to a shot of the two of them in the doorway, and the album cover has changed to the "Columbia Jazz Masters" reissue cover from much later.
When Ike is setting down to dinner with Maggie and her family, they are eating crabs and Ike and Maggie's father are discussing the weddings. Ike looses grip on his mallet and it goes flying across the room behind him. In the next scene it shows Maggie's father looking at where Ike would have been sitting while talking but Ike is shown still up from the table retrieving his mallet and not at the table at all.
When Ike comes into Curl Up And Dye for the first time, Maggie calls Peggy over and points to the counter at the article with Ike's picture (and the devil horns and pitch fork that has been added on). It is originally on taped on the counter, but in the next shot is taped onto the mirror.
At the baseball game, when Ike first comes up to Maggie and Peggy's row, behind and to the right of them is a blond-haired woman talking every so often to a black guy. Halfway through the scene, there is a different black guy talking to the same blond-haired woman (although he is wearing the same clothes as the other one).
When Maggie is presumably listening to the tape she stole from Ike (Richard Gere), the audio track plays Miles Davis's song "it never entered my mind" which does not appear as a song listing on the tape.
During the softball game, the pitches appear to be coming in slow and with an arch which would indicate slow-pitch. In slow-pitch, there is no stealing; therefore, Cory Fleming would not have been allowed to steal 3rd base. All the catcher had to do was to throw to 2nd base to force out Fleming.
When Ike and Maggie drive away from the tavern in Ike's convertible, after putting Maggie's father in his truck to "sleep it off", their hair should be blowing during the drive in the open convertible - especially Maggie's long mane. Their hair is perfectly still.
During one of Maggie's wedding videos that Ike is watching, we see Maggie running away from the altar with the ring bearer (a young boy) being dragged behind her by holding onto the train of her wedding gown. The video he watches has points of view that would suggest at times the bride is holding the video camera and pointing at the boy being dragged, and it shows another point of view as if the little boy is holding the video camera and videotaping the bride running out of the church.
Ike's controversial article was written before he got the idea for it. In the beginning of the movie, the newspaper article George Swilling is reading while Ike hits on the woman playing darts is titled "What's to see in blind dates," but the content of that article is read by the montage of characters one scene later.
The goof item below may give away important plot points.
During her first wedding with Ike, Maggie leaves the church through an open window in the day care center. On the window sill and spread out onto the grass is a sheet, as if to protect her wedding gown. There is no other reason for it to be there.