Audio problem: In the scene where Sharon Stone is talking to Joe Pesci about how De Niro had his guys beat up James Woods, at one point Sharon Stone says, "Oh C'mon." If you look closely her mouth doesn't move at all. Also if you listen closely, that line comes out on surround sound. When she continues her line it comes out on mono. It was obviously recorded.
Audio problem: During the scene with the astronauts building the makeshift CO2 scrubber, Jack and Fred are getting the tape ready and tearing it lengthwise. Capgo says, "Alright," indicating he was going to move to the next step. Fred responds, "Hold on, Houston." Bill Paxton's mouth does not move, and he is visible.