Continuity mistake: When Marge is talking to Lisa in her room about Band Practice, Lisa is reading comics, eating potato chips, and there is a drink by her as well. The drink container starts out green with a light purple label, then goes to being grey with a red label then as Marge tells her story, the colours of the drink change again twice. (00:10:00 - 00:10:55)
Continuity mistake: Two guards take down and eat the embassy flag. But when the Simpsons look down at the frogs at the embassy, the flag is still up on the pole.
Revealing mistake: When Lisa is explaining to the curator of the museum why she didn't tell the crowd of what she learned about Jebediah Springfield, if you look in the background none of the people on the far sidewalk are moving, almost frozen in place with some of them with their arms in the air yet everyone and everything in the parade keeps moving right along.
Audio problem: Ms. Krabappel is telling Bart about the laundry list of sicknesses he had to get out of the test. You can see her mouth doesn't match up when she mentions "...and that unfortunate case of rabies." The studio actually changed what Ms. Krabappel originally said which was "and that unfortunate case of "Tourette's Syndrome." [Some reports say that the original line of Tourette's Syndrome was left in syndications in certain areas. On the DVD version the rabies line has been used]. (00:16:00)
Continuity mistake: In the scene where Bart is in the Court House, when we first see everyone, on the Judges table there is no gavel, yet when the shot changes, a gavel appears. (00:05:20)
Continuity mistake: When Homer says, "You can't take our donuts," his hat is red. But in the next shot and in every other shot of Homer, his hat is blue. This is pointed out on the audio commentary on the Season 4 DVD. (00:12:35)
Continuity mistake: When Bart skates towards Homer's car, attempting to skate over it, the distance between the car and Bart changes between shots. (00:11:00)
Audio problem: When Bart is attempting to skate over Homer's car with his friends watching, Milhouse says 'You're crazy Bart.' but his mouth never moves. (00:10:55)
Continuity mistake: When George and Homer burst out of the manhole, there is a shot of the Simpsons' house covered in mud, then a quick one of it totally clean, then another when it's muddy again.
Raging Abe Simpson and His Grumbling Grandson in 'The Curse of the Flying Hellfish' - S7-E22
Continuity mistake: Grampa loses his red slipper as he is pulled by Mr. Burns' boat. Later it is back on his foot.
Continuity mistake: When the garbage man is asking Homer if he learned anything from love day, his cigarette is in his hand, but in the next shot when Homer says, "That was yesterday moron", the cigarette is now in his mouth.
Continuity mistake: Marge tells Bart not feed Maggie the Monopoly houses. Bart shows the box and says that there's enough of them. The shot later, the box has disappeared. (00:16:15)
Much Apu About Nothing - S7-E23
Continuity mistake: When Barney is tranquilised, he falls with his mouth closed. In the following shots, it's open, closed, then open again.
Continuity mistake: During the "We Do" song, there is a character at the top of the screen who keeps changing colour. I think it might be Dr Hibbert, but his skin colour keeps flickering to yellow.
Diatribe of a Mad Housewife - S15-E10
Continuity mistake: When we first see the book-reading Ms.Krabbapple is sitting at the end of the row. The next time, Groundskeeper Willie is there. And the third time we see the audience, Apu has appeared in The Front row as well. (00:02:25)
Missionary: Impossible - S11-E15
Continuity mistake: This mistake happens twice in the episode. At first, when Homer arrives on the island, he gives the islanders some bibles and says "Knock yourself out." Ack says that they cannot read. Yet later when Homer is revealing the casino, Ack reads "The Lucky Savage-?"
Suggested correction: Homer had been there for a while when the casino had finished construction. He could have taught Ack to read.
'Tis the Fifteenth Season - S15-E7
Continuity mistake: After the family discover the astrolobe, the gift tag disappears from its wrapping. (00:07:25)
Burns Verkaufen der Kraftwerk - S3-E11
Continuity mistake: When Carl complains that he can't be fired, everybody behind him, Homer and Lenny has disappeared. (00:09:00)
Burns Verkaufen der Kraftwerk - S3-E11
Continuity mistake: As Horst and the guy talks to Homer, the guy is holding a folder in the first shot, then it suddenly disappears, before appearing on the desk without him putting it there. (00:12:45)
Lisa's Pony - S3-E8
Continuity mistake: When Lisa calls Homer at work, Homer picks up the phone on his left side. Instantly after, we see him hang the phone up on his right side. (00:19:00)
