Audio problem: When Kevin is going through Buzz's private things he finds a picture of his girlfriend. Sickened by her appearance, he smashes the picture. But the smashing sound starts before he hits it. (00:22:05)
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 the carolers come to sing for the Kranks, it is professional-quality singing. Then the neighbors join and you can hear that more people are singing, and the quality of the singing is realistically worse(the neighbors can't sing well.) After a few shots of the carolers AND the neighbors singing, the sound goes back to just the carolers singing, though you still see the neighbors singing on screen.
Audio problem: Just after Hans addresses McClane by his name over the radio, we can hear Powell say, "Better get ahold of someone at dispatch," but his mouth movements don't match what we hear. (01:18:50)
Audio problem: When George is talking to Harry on the phone regarding being decorated with a medal of honor, he is at his office. The guy to the right of him starts to say "what is he saying?" but the audio cuts off just before he finishes "saying." The scene cuts to a closer shot of George talking, so why did the audio cut off?