I'm surprised most people haven't noticed this sync bug. You all must be watching videos a few minutes long. Watch a movie lasting an hour and a half and you'll soon see it. After 20 minutes, the sync is noticably off. After 40, it's off so badly it makes the rest of the file unwatchable. At the end of the file, the sync is off almost by a full three seconds.
Perhaps this depends on which type of file you're watching? MorphOS doesn't detect too many of my VideoCDs, so I tried it out with a divx file I had around. It was pretty far out of sync by the end of it.