Corrected entry: In one scene, when Bart is a child, he and Homer are watching Krusty and Sideshow Mel. However Sideshow Mel appeared only after Sideshow Bob was arrested, as his replacement. Krusty even mentions this in another episode, saying something like "The guy I got to replace you doesn't hold a candle to you Bob".
Corrected entry: When Sideshow Bob says that he hasn't made any progress on catching the person who is trying to kill Homer, he says, "Go ahead, shock me." and hands Marge the shocking remote. Sideshow Bob has been trying to get the remote ever since he was introduced into the episode. Why, if he has it, does he give it to Marge instead of taking it and trying to kill Bart, which he does at the end of the episode?
Corrected entry: During this episode, Krusty is seen looking at the Simpsons videos and some Jewish magazines. Krusty can obviously understand what they are saying (as he seems eager to watch a video he finds at the Simpsons house and he gets very upset looking at a Jewish father/son magazine). However, he is supposed to be illiterate, reinforced by the fact that Krusty couldn't read Bart's letter early in the same episode.
Corrected entry: When Mr Burns asks Larry about his life, he mentions that he stayed at the orphanage until he was 18, and then got the job at the stall. He also mentions the small detail of seeing a blimp. Yet at the end of the episode, he says he has a wife and kids. Wouldn't he have mentioned them earlier to Mr Burns, if he included such a petty detail as a blimp?