00:12:20 - 00:14:15 When Bart and Lisa are watching TV, Bart says "I've got my ticket" and pats the ticket inside his shirt pocket (which there is none). But later in that same scene when they are still watching TV, both the pocket and the ticket have gone.
00:14:50 When Maggie is driving Homer's car, a man is behind her. He is seen waving his left arm but when the shot changes to Maggie he is waving his right arm.
The camera shows Homer and Marge's feet's walking on the front path to the house, yet they come in the back door.
When Marge is talking to Ms. Krabappel, Marge is "punished" by writing lines on the blackboard. In the first shot of her doing so she has written the line 9 times, but in the next shot there are 11 lines.
When there is a queue to see the movie, it stretches right back to the Simpson house, and we see Bart looking through the window. However, when Homer talks to Bart whilst sitting on the window, the queue has disappeared.
Bart melts an action figure in the microwave; however, microwaves don't work that way. They are only absorbed by water, fat and sugar - none of which are in plastic action figures.
In the "Itchy and Scratchy beating up Hitler" cartoon, FDR shows up to kick Hitler's body. While Franklin D. Roosevelt was paraplegic, this fact was downplayed or ignored in popular media portrayals (and it's a humorous cartoon anyway).
When Maggie is seen driving the family car, she can see over the steering wheel, however it would be impossible for her legs to reach the gas pedal.
When Nelson blinks right before Milhouse says "No one who saw the movie would say that", Nelson's right eyelid is white.
In one scene, Itchy ties Scratchy up to a railroad track about to run him over with a train and Scratchy tries frantically later. A second later, his entire body disappears, but his arms are still moving.
On the Itchy and Scratchy Movie ad, Itchy rips Scratchy's brain apart while laughing, but his mouth doesn't move.
00:04:25 When Homer reads the car bumper sticker 'My child is on the honor roll at Springfield Elementary', his mouth doesn't move.
Bart's mouth doesn't move when he laughs after saying "Now's our chance to be bad."