This is my problem: I usued VirtualDub to add a subtitle to a movie, but the audio goes out-of-sync with the video when the movie goes on playing (e.g. it's OK in-sync at the beginning of the movie, goes out-of-sync +0.5 sec after 1h of movie and +1 sec after 2hrs). Please note that this is the first time that happens to me with a video (I always use DivX multipass to compress the video and it never happened to me before) AND I listened to the original movie which was OK. What have I done, probably? What can I do to correct the movie AND to avoid to do the same thing again? Thanks.