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: When Nicky is at the airport having his suitcase searched by Customs, he says "If you find any cash in there we'll whack it up with ya" but his lips don't move in unison with the sentence. (00:27:50)
Audio problem: When Pat Webb is reading aloud the newspaper article about Sam Rothstein, his lips don't match when he begins the sentence reading "the Midwest bookmaker", and also the audio sounds spliced in. (01:31:15)