When Chelsea pulls out a bag of chips from her locker, the bag is closed but when Raven pulls out a chip from the bag the bag is open.
When Raven is speaking to Chelsea in the end (bathroom scene) and Raven saying her line "but we don't need boyfriends to have fun..." the camera angle turns to a straight on view (you can see the stalls and Chelsea and Raven, like you are looking from the mirror) and you can tell the lines are dubbed in.
In the phone conversation scene between Raven and Chelsea, after Cory licks the phone, Raven says "For Your FYI". This is obviously incorrect, as in effect she is saying "For your, for your information."