If everything is timed properly in the fla then just export the video only and combine video and audio in a third party program like sony vegas. I gave up on messing with the Audio/video sync in flash a while ago because that program is terrible with memory
RatherRandomReality
Try having layers only for sounds, nothing else. When there is no sound playing, have it play audio of silence. Have it play audio on all audio layers from frame 1 to last frame no exceptions. It works for me.
bocodamondo
hmm...this might actually work, i'll give it a try