Audio problem: There are several times in the scene at the party where Fat Albert supposedly says "Hey hey hey" but his mouth is closed.
Audio problem: In the scene where Jack returns to the motel in the morning (after his first night with Stephanie), she's waiting for him on her motorcycle. When Jack goes back downstairs and gets on the back of the motorcycle, the sound effect is that of a revving bike engine, but you can see that Stephanie's right hand (the throttle hand) is not moving at all.
Audio problem: At the end, as Dax rescues Sahara and loads her into the evac shuttle, he steps away from the craft. Bugs are swarming the scene, but it is apparent that Dax is staying behind. Sahara cries out, "You stay here, you die!" and we hear Dax reply, "Murderers don't go home," which is an overdub. His mouth visibly says something very different with several more syllables.
Audio problem: In the very first scene of the movie when Bobby is recreating his performance at the Coconut Grove, the actions of the band are out of sync with the music we hear. (Bobby is in sync, but the band is not.) Watch the hands of the drummer and the band leader: The entire scene is out of sync, but when the drummer moves to the ride cymbal you can easily see he is ahead of the music, and when the band leader gives the band cues for accents, his hand movements are behind the music and therefore happen too late.