Continuity mistake: First day in class, when Hoager "beeps" at Jesse, Mrs. Myers writes two words. The word "verb" is over the word "subject" on the board, in the close-up. After she turns around, in the following shots, the word "predicate" appears, disappears, then reappears and "subject" is written over "verb" now. Additionally, during this scene, all the other writing on the blackboard changes between shots as well.
Other mistake: During the credits, Squogre is spelled wrong, as revealed in the DVD commentary. It's spelled as "Sqouger"