Continuity mistake: In the scene where Santa is getting married, just after they kiss and Santa looks like Santa again, you can see in the bottom left hand corner Bernard and Curtis giving each other the thumbs up. In the very next shot, it repeats them doing this again only in a close up. (02:33:00)
Continuity mistake: When Charlie goes down the rope (in the beginning of the film) to spray paint the wall in the gym, the rope hangs tight from his point of view, but loose from his girlfriend's point of view.
Continuity mistake: In the scene where the clone Santa is sitting at his desk reading the book of rules, one of the elves gives him some cocoa and he sets his magnifying glass down. In the next shot, the magnifying glass isn't there, and in the next one it has magically reappeared.