Continuity mistake: Near the end of the movie, when Justin's mom is about to read the letters that he has sent to Santa and Mrs. Claus, in the shot of the back of the first envelope the flap as been folded in to close the envelope. But, in the next shot, when Justin's mom turns the envelope over to open it, the envelope has been licked shut.
Continuity mistake: There are only 2 kids in the child's bedroom, but when you see the TV commercial they are watching early in the movie, you see FOUR children reflected in the screen. Way to the left is a boy dressed in white or light blue, leaning over a boy in dark blue to the right, then next is Dylan or Cole Sprouce (actor), and the other child actor, dressed in white. (00:04:50)