Are you using a firewire DV bridge to view picture on a TV? When using this method you must set a 22 quarter frame offset. If this is the case, and you have been working without an offset, you are technically not in synch with picture. Then, when you go to make the bounce to movie, you would have an offset problem. A little tricky until you figure this out. Had the same problem when I started. I would check your picture sync with the movie open on the computer screen with a zero quarterframe offset. Once you are correctly in Sync, it should bounce fine. Good luck!