Other mistake: 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. (00:01:45)
Other mistake: In the shot before Marge says she will marry Homer, the right side of the screen is cut off a little. (00:08:25)
Mr. Lisa Goes to Washington - S3-E2
Other mistake: The first time we see all three children staring at the TV, the interior of the Simpson house seems different. (00:02:30)
Other mistake: When Marge sees the letter from Homer, she says "You won't see me again until I'm a man." On the paper though, it reads 'But you will not see me-' and the sentence is cut off, and the rest of the paper is blank. (00:16:10)
Other mistake: When the wheel falls off Bart's skateboard, in the shot where he curves left sharply, you don't see the school in the background. How could he be at the social club if he just left school? (00:05:20)
Other mistake: When Bart and Homer do a test drive on their race car, it is daytime, when supposed to be night-time. (00:11:50)
Like Father, Like Klown - S3-E6
Other mistake: When Krusty dials '1-909-SEX-CHAT,' he presses '90190' on the phone. (00:03:50)
Other mistake: When Homer talks to Bart and Lisa through the window, he is standing almost straight up, but considering he is right in front of the TV in the next shot, he would've had to crouch down a little. (00:03:50)
Like Father, Like Klown - S3-E6
Other mistake: At the very end, when Krusty's father throws the pie in his face, the food instantly comes off his face. (00:21:40)
Radio Bart - S3-E13
Other mistake: When Bart falls down the well because Eddie tripped the rope, why would there be rocks falling down with him? (00:16:00)
Other mistake: When Homer leaves the window, the TV is in a different area of the living room. (00:03:50)
Burns Verkaufen der Kraftwerk - S3-E11
Other mistake: After the scene where Mr. Burns gives Smithers his picture of him and Elvis Presley, Homer asks Lisa a couple of questions about Germany. At the beginning of this brief scene, Lisa is reading a book, and from her point of view, her eyes are moving from right to left, which shows she is reading the wrong way on a single page. (00:11:10)
Other mistake: When Bart sees that Santa's Little Helper ate his homework, and the camera moves really fast, you can see that the Krusty Doll and picture frame have vanished from the desk beside his bed. (00:00:55 - 00:01:50)
Other mistake: During the shot when Marge asks Homer who 'Hank Jones' is, you can see that the couch curves down on the left side of the screen, therefore putting her on the other side of the couch. (00:07:40)
Tree House of Horror II: A Simpsons Halloween - S3-E7
Other mistake: As Mr. Burns' fireplace rotates, the items on the top should have fallen off, but they didn't. They also disappear/reappear between frames. (00:16:10)
Other mistake: When we first see Nelson's Roadkill 2000, Nelson is moving backwards, though we see his legs as moving forward. (00:13:25)
Other mistake: How can Sideshow Bob make the "I H8 BART" licence plate if there are no number keys on the keyboard? (00:04:45)
Other mistake: Near the beginning of the episode when Selma and Sideshow Bob arrive at the Simpsons' house, Bart and Lisa scream and hide behind Marge. Selma says "What the - ?" but the DVD subtitles say that Marge says it. It is shown "MARGE: What the - ?". (00:02:30)
Other mistake: When the pupils are doing the test at school, you hear Miss Hoover say a question with three possible answers; but 1) There are 5 possible answers on the test when we see Lisa doing it, and 2) Miss Hoover says the 60th question, but Lisa looks to be nowhere near the 60th question.
Lisa's Pony - S3-E8
Other mistake: When Lisa rings Homer to tell him that she loves him, the shot of her talking is re-used from "Bart's Dog Gets an F." We can tell this because her cheeks inexplicably appear puffed up (in "Bart's Dog Gets an F" she had mumps).