Other: There are two mistakes when Bart calls the Krusty Hotline: 1, The cereal box says the phone number is '1-909-O-U-KLOWN.' Bart presses eight buttons on the phone. 2, as he is dialing, you can HEAR seven buttons being pressed.

Continuity: When Mr. Burns notices that Homer is wearing a pink shirt to work, when he pauses and zooms in the video, Homer is looking almost directly at the camera. In the next shot, though, he is looking more to his left. The people surrounding him also change.

Audio problem: When Bart says "Krusty Hotline" his mouth doesn't move.

Continuity: Bart opens the house's front door, then the shot zooms out to show us that all of Springfield is at the Simpson house. In the next shot with Mayor Quimby the door is suddenly closed.

Audio problem: When Michael and Bart are playing a song to Lisa, Bart uses her bin as a drum. Sometimes you hear tapping, but Bart doesn't touch the bin.

Audio problem: When the lady is asking questions to Homer before Lisa wins the trip to Washington, what she says doesn't match her mouth.

Other: The first time we see all three children staring at the TV, the interior of the Simpson house seems different.

Continuity: When Lisa approaches the Abe Lincoln statue, there is an old person near her. In the next shot, there are three people suddenly surrounding her.

Audio problem: When Lisa is reading her speech for the essay contest, what she says does not match her mouth movements.

Plot hole: The Simpsons take a flight to Washington D.C. for Lisa's speech. But it is revealed in a later episode that Marge has a fear of flying. This was before it was discovered that she had a fear of flying.

Factual error: When the piano keys are shown when it is played at the end of the episode, it is shown having one black key each time. Real pianos start off with three black keys, then two, then three and so on.

Audio problem: During Marge and Homer's argument at the beginning, when Homer says that Ned Flanders is a jerk, his mouth doesn't match what he's saying.

Continuity: At the beginning, when there is an overhead shot of the Simpsons' lawn, the broken lawn mower has disappeared.

Continuity: When Mr. Burns is notified about the Leftorium, the can and can opener have disappeared from Smithers' hands.

Other: At the end, you can briefly see Dr. Marvin Monroe. The cigar he is holding instantly changes from white to brown.

Revealing: When Barney is drinking beer at Moe's Tavern, his chest is, for one frame, the same color as his shirt.

Other: When Rod and Todd Flanders are roasting marshmallows in the car, Todd's marshmallow was the only one above the lighter, even though both of them have turned black.

Continuity: When Homer goes to the barbecue, he grabs a plate of burgers. There isn't a burger at the top of the pile. However, when Flanders talks to him there is a burger on the top.

Other: When Homer discovers that the Leftorium is going out of business, there is a sign that says 'Coming Soon: Gum for Less' beside the store. Later on, though, Ned says the new store is becoming 'Libertarian Party Headquarters.'

Continuity: When Homer buys Ned's living room for $75, Bart is wearing a pink "Ned loves Maude" T-Shirt but by the end of the scene where Bart says "Hands off my china hutch." his shirt is the standard orange shirt.