When Mr. Burns is lying on the table before the Simpsons enter his body, he is wearing briefs. However, when the Simpsons are inside him, he is wearing boxers.
When Ned can see how people are going to die he tells Hans Moleman to wiggle out of his shoes,If you look there is no sewer anywhere near Ned but when he drops Moleman there is a sewer next to him that was not there before.
At the end of the Mutton-Chop Murderer segment, Ralphie and the Inspector are back in the opium den. The Inspector is in a chair, while Ralphie is on a beanbag. Yet when they fly out of the castle, they're both on a bed.