Corrected entry: In the Knowledgeium, when Professor Frink says 'No more pictures,' his lips don't move.
Tree House of Horror VIII - S9-E4
Corrected entry: When the French launch their neutron bomb at Springfield, on it is written "Le bombe à neutron". The proper spelling is "La bombe à neutrons"
Correction: Actually not a mistake. Thats the joke, USA's ignorance of the world around them.
Corrected entry: Homer shoots the TV on, and talks to the other members, then when you next see a shot of the TV screen, it has turned off. And it can't have broke because other bullet holes can be seen too which didn't break it.
Corrected entry: During the opening dream sequence on the "Planet of the Donuts", we get our first glimpse of the monster donut that will eat Homer when his shadow looms over Homer. In this shot the shadow is of a "regular" donut, i.e., one with a hole. In the next shot we see that the monster's hole area has teeth and is filled in with black; in other words, its hole is a regular mouth. As such it could not have had light shining through it to make the donut hole in his shadow.
Correction: It is a dream. Dreams don't make any sense and are not bound by any laws of reality. The donut could have grown teeth and a mouth between shots.
Corrected entry: There were five judges at Homer's court martial, however, four of them walk away, so there should be one left, but all five chairs are empty.
Correction: There is no requirement that they show every judge walking off. Since the judges who speak are shown in mid-shots that do not allow us to see all of them at once, there is no reason to think the 5th judge could not have walked off quietly without speaking while we were watching one of the others.
Corrected entry: Marge is very nervous when Homer brings a gun into the Simpson house. But she never had problems with guns in the house when she was a cop.
Bart Carny - S9-E12
Corrected entry: The Simpsons arrive back at their house and discover that the 2 carnival workers they let live with them have boarded up every window and way into the house. However, when they are in the tree-house, you can see the windows on the upper-floor have remained un-boarded.
Correction: We never actually see the back of the house when the Simpsons arrive so we can't safely assume that it's all boarded up. More importantly perhaps, we don't see the back of the house until several hours later, so it's quite possible they simply took the boards off.
The City of New York vs. Homer Simpson - S9-E1
Corrected entry: The Simpsons don't only have one car. Why doesn't Homer drive the red station wagon that appears in almost every episode, instead of using a scooter?
The City of New York vs. Homer Simpson - S9-E1
Corrected entry: Homers watch keeps disappearing and reappearing between shots throughout the whole episode.
Correction: That mistake is already listed.
Correction: I'm not sure what you're seeing, but his lips do move when he says this.