Tremors 2 (1996)

Audio problem: In the scene where the Grabboid is pulling the truck with the chain attached and the guy is trying to shoot it, the gun noises do not match up with the muzzle flashes at all. At one point it is obvious he fires 2 shots, and yet 4 "bangs" can be heard.

Audio problem: There is a scene just after Earl and the new guy arrive at their base, when a truck (driven by one of the Mexicans I think) pulls up from the left hand side of the shot. If you listen you can only hear the truck's engine from when it comes into shot. This suggests that it was waiting just off shot and then drove in, rather than coming from any distance as you would have heard it approach.