Audio problem: When Warren comes back to the store with a gun and is talking to Deb, he says "My name isn't f - -ing Warren." The store employees are peeking around the wall at this. They say "His name isn't f - -ing Warren," to each other but if you read their lips they're saying "His name isn't Warren." From the Fan Edition DVD.
Continuity mistake: There is a scene where everyone is dancing. It's towards the end but not at the very end. One of the employees of the record store takes his shirt off. Then the camera cuts back and you see the entire group of people dancing. If you look at him he has his shirt back on. Then a couple of shots later he has it back off again.
Trivia: Just after Lucas tells Joe he's a 'superb manager', Joe drags him off to beat him up in his office. When he takes him into the back, you see a girl standing in the doorway. She is the same girl you see when Mark and AJ enter the store at the beginning. Her character was called Lily and she was cut out of the film. Her name is also still in the credits.