Audio problem: When the first assassin runs out of bullets shortly after coming through the apartment window, his gun makes a series of rapid clicks as if dry firing full-auto, but real guns, even full-auto ones, don't keep on clicking when empty. It should either make a single click, or a nearly inaudible one. (00:44:16)
Audio problem: When Abby, an elf, is about to tell Santa that Charlie is on the naughty list, she says something about 'Brazilian cocoa beans'. As this line is heard, you can see that her mouth is moving completely differently from the words we hear.
Audio problem: When Mathayus and his friends are attacking Memnon's palace, there is a scene where Memnon's general rides at Balthazar on a horse, but then falls off. Balthazar holds a spear at his neck. The shot then changes so we can't see the general and he stabs him and he screams loudly. But if the spear went through his neck (as it should have, as it didn't move anywhere but down) he should not have been able to scream. (01:16:55)
Audio problem: When Juni falls into the "volcano", Carmen attaches a harness to a branch and dives after him. She grabs him and then seconds later the harness snaps. It then cuts to a shot of Juni and Carmen plummeting down the volcano, and you hear Carmen yell "Juni!" yet her mouth is shut tight. (00:48:05)Hamster
Audio problem: In the mountain battle scene when Xander is in the airplane, he says: "Get me along that tower." His lips don't match with what he says, indicating this line was added during post-production.