Homer's Triple Bypass - S4-E11
Continuity mistake: When Krusty takes off his shirt, the superfluous third nipple and cattle skull birthmark shown in "Kamp Krusty" are not on his chest. (00:14:50)
So It Has Come to This: The Simpsons Clip Show - S4-E18
Audio problem: After Homer puts the old milk in the fridge and Bart takes a drink from it you will then see Marge use a fork to take the milk out of the carton. Marge says "woof" but her mouth does not move in sequence with the audio.
Continuity mistake: When the family is at dinner, there is a top down view which zooms in on them from above. In this shot there is no newspaper on the chest (to Homer's left). In the next shot of Homer a newspaper has appeared. (00:07:50)
A Streetcar Named Marge - S4-E2
Continuity mistake: As Marge is about to leave for her first audition, she walks across the room and she is wearing white slip-on shoes. Then her and Homer talk for a bit, then when it cuts to a wider shot after they talk, she now has her red flat-heels on. (00:03:30 - 00:04:00)
Marge vs. the Monorail - S4-E12
Audio problem: When goes to the Monorail Café, the woman there says to Marge "Go away" but her mouth doesn't move.
Homer's Triple Bypass - S4-E11
Continuity mistake: When Dr Nick visits Homer for the first time, he leaves the door open. But later before the reporters come to the door, the door is closed. (00:13:40)
Continuity mistake: In one scene Bart is swinging on a washing line then we see Homer talk to Marge and he says "He'll soon get tired of it" then it goes back to Bart and he is facing the opposite direction and he is swinging on two washing lines. (00:04:22)
Last Exit to Springfield - S4-E17
Revealing mistake: When we see Lisa singing and playing the guitar for the second time, if you look to the right you can see a blue mark on the building that is behind her (On the middle turquoise stripe). It appears and disappears twice.
Continuity mistake: When the police talk about the bumper cars getting stolen by Jimbo Jones, you see him and his 2 friends riding off in bumper cars. From the side angle, there are 2 blue and 1 red car, but from the rear view, there is 1 blue, l red, and 1 green car.
Continuity mistake: In this episode Hans Moleman's skin colour is yellow. However in "Duffless " his skin colour is brown and in other episodes it is a dark yellow-green colour.
Marge vs. the Monorail - S4-E12
Audio problem: When Mr Lanley is playing the piano, he plays some chords with both hands. During the line "Put up your hands and raise your voice", he plays the same chords, but at a different note, with only one hand.
Continuity mistake: When it is announced that Amber is the winner of the contest, and Lisa is runner-up, the stands in the back of the stage are empty. However, when Lisa walks off, all the contestants are back on the stands. (00:15:00)
Other mistake: When Lisa checks Marge's resume, she reads it and turns it over. But there is no text on the back as there should be. (00:06:30)
Continuity mistake: When Homer is sitting in the Frying Dutchman with the crowd gathered round looking at him, the Captain invites people in. Some start walking in, but in the next shot where they are all gathered round again, it is the same group of people again. (00:17:00)
So It Has Come to This: The Simpsons Clip Show - S4-E18
Audio problem: When Lisa explains the origin of April Fools Day, we hear Homer, Marge, Bart and Lisa chanting "Blood For Baal." But, we see that Lisa is not taking part in the ritual and her mouth isn't moving. (00:02:15)
Continuity mistake: Willie rips off his entire shirt before he fights the wolf, but in the next scene, when he is wrestling the wolf, he is wearing a torn-up shirt. (00:18:40)
Continuity mistake: At Moe's, when Homer takes hold of the telephone its color is red, but then changes to blue as he speaks to Marge. (00:02:30)