Audio problem: When Vader is talking to an Imperial officer in the hangar in the Death Star, when the officer says, "It must be a decoy, sir. Several of the escape pods have been jettisoned." his head is shown from behind, but his profile shows his mouth is moving before the words are heard. (01:03:55)
Audio problem: After Bond sets the timer on the bomb at the end, the ticks don't add up. There's a definite tick each second, and you can count 12 of them after he starts it, then we cut back to the bomb and only 7 seconds have passed. (As a vague trivia aside, coincidence though it is, on the UK DVD he pulls the pin out at the DVD second timer ticks onto "07").
Audio problem: In a wide view of the mice singing "Rescue Aid Society" at the United Nations, a mouse is hitting his drum with a drumstick, but no sounds are coming out of it.