Continuity mistake: There is a scene where the Chipmunks and Chipettes are singing the song "Girls of Rock and Roll." In that scene, it shows the boys walking up the stairs together and from left to right the order is: Simon, Alvin & Theodore. The shot goes to the girls then back to the guys. The order of the guys have swithed: (left to right) Theodore, Alvin & Simon.
Continuity mistake: During the "Girls of Rock N Roll" part, at one point, Jeanette and Eleanore do a ballet twirl together as they say, "Yeah we're the girls of rock and roll-la!" If you look, Jeanette's hair flickers from a redish brown color, to a duller brown right after they say "roll-la" dramatically. Not only does it not have anything to do with the spot light, but it's quite noticeable.