Sound going out of sync when exported
I am making a relatively simple movie, trying to sync it up to a 40 second or so sound clip I recorded from a movie. I've lip synced the dialogue and synced to the sound effects, looks good when I play it quick, however, when I test movie or export it to swf, the animation gets more and more off sync to the sound clip as the animation progresses.
Like at the beginning of the scene the sound is a split second before the mouth movement, then by the end of the animation the sound is a little over a second before the movement.
I can't figure this out, and I'd rather not guesstimate and move stuff forward to compinsate. thanks for any help.