Continuity: When you see a shot of the church from outside in the scene where the bee sharps sing there, look closely at the sign. You can see that it says 'Also: The Bee Sharps', only they don't name themselves that until later on in that episode.

Audio problem: When Homer is playing on the piano, he says the word "fault". When he says this you can hear a key being pressed but Homer doesn't touch any keys.

Continuity: When Homer is talking to George Harrison, he sees that he has a brownie. Then he rushes over to a pile of brownies and starts scoffing them down. The pile of brownies doesn't get smaller.

Audio problem: When the Bee Sharps are singing 'Goodbye my Coney Island Baby' next to the Statue of liberty, you can hear Chief Wiggum's voice singing with the other members of the group, but he got chucked out of the group earlier on in the episode.

Audio problem: In the scene where the Be Sharps first sing "Coney Island Babe" (I don't know what the song's really called) at Moe's, Skinner sings the rhythm. But when they sing the last few lines, you can still hear Skinner's part, but his mouth is moving like the rest of the group.

Other: In the flashback where Marge is making a model of Homer, the models head falls off and Santa's Little Helper picks it up, but the Simpsons did not own the dog back then.

Other: When the Be Sharps are singing at the Statue of Liberty, in some shots the stars in the sky are black.

Other: When Bart and Lisa are looking at records, there is a picture of Homer. He had hair at the time the record was made, and the hat he's wearing isn't big enough to cover it, but there's none visible as there should be.

Continuity: At the sale, when Bart and Lisa first find 'The Bee Sharps' album, the order of the records in the stack change in subsequent shots.

Audio problem: When grandpa is listening to the radio, he says something like 'oh.', but his lips are not moving.

Plot hole: During all of the flashbacks, Homer is in stage 1 hair loss (birth of Bart), but shouldn't he have the amount of hair he had after finding out about Lisa's birth? If the flash backs did occur 8 years ago, shouldn't Marge be pregnant and homer be bald?

Continuity: At the end of the episode, while the B-sharps are singing on top of Moe's Cavern, the guy climbing the building asks the people to look at him. As he moves his hands, his gloves change color from red to white and back to red.

Audio problem: After Jasper has sung on the stage to Homer, Apu and Skinner, they simultaneously say "Next". But if you listen carefully you can't hear Homer's voice.

Continuity: In the deleted scene where the Be Sharps unveil 'Donut Records', Barney's hair flashes red a couple of times in the close-up of the band. (This counts as a mistake because the scene was fully animated and then cut later.).

Continuity: At the beginning of the episode when we see MacBain on TV he goes through a curtain, the curtain stays open for a second even though he isn't touching it.

Audio problem: When Homer is talking to the family about their complaints about the nerds, he says something that ends in "where we can all live in harmony". When he says this the audio does not match his mouth movements.

Other: Just after Homer has used the proton accelerator, Dean talks to him. In this scene he is writing something on a piece of paper, but he writes on the same line every time. He finishes writing on that line, then starts on it again.

Continuity: The colour of the alien poster in the nerds' room changes from pink to blue.

Audio problem: At the end of the episode, there is a clip in 1 million AD. Mr Burns gets Bobo (his teddy bear) and says something to him. When he says this the lip sync is a little bit out as the audio doesn't match what he's saying.

Revealing: When we see people digging Bobo out of the ice, they put him in a bag. If you look carefully you can see another Bobo put in another bag just before the shot changes.