Continuity mistake: In "Hex and the City", when Homer, Bart, Lisa and Maggie are eating their breakfast at the table, they see Marge with a blue beard and Homer spits some food on the table. In the next shot, the food has gone, and when Homer goes to strangle Bart, it is back again.
Continuity mistake: In "Hex and the City", when Marge, Bart and Lisa are at the Fortune Teller's office, you can see the Fortune Teller has three cards in front of her on the table. When Homer arrives, the cards have gone, and later on in the scene they are back on the table again.
Continuity mistake: In "Citizen Kang", when Homer pulls off the masks off the fake Clinton and Dole at the White House, the two transform into aliens and you can see Homer is between them. In the next shot, Homer is missing, and in the shot after that, he is back again.