When Homer and Lisa are playing in the radiation suits, as the chairs are spinning, Homer is laughing, but his mouth isn't moving.
Lisa and Homer play in radiation suits. Lisa's fits perfectly as does Homer's, yet when they are seen hanging on the wall they are the same size.
When Homer is working at the power plant, his necktie disappears and reappears during several scenes.
When Bart, Milhouse and Nelson leave Moe's, there is a can on the right hand side of the ground. When Martin and his mechanical dog first appear in the next shot, the can is gone.
When Smithers eats a Jolly Rancher, his mouth makes a chewing sound, but Jolly Ranchers are a hard candy that were not in a chewable form in 1996 when this episode aired.
When Nelson leans over and slaps the guy in the car next to them, the man turns his car around and travels in the same lane which he was going forward in.
The Knoxville courier asks Bart if he can deliver 500 Big Macs to Marlon Brando's island, but he actually has 3 boxes ready for Bart that each say, "250 Count", totalling 750 Big Macs.