Audio sync problem in RC1 build 803

[VideoMad]

Video seems to be ahead of the audio by about half of a second. The problem isn't limited to one or two badly ripped avi files, it happens with every avi that I have. I did some tests with three avi movies and several media apps, and recorded how much the audio seemed to be delayed:

hudsucker proxy (divx5 / mp3)
media player - video slightly ahead
bsplayer windowed - video slightly ahead
bsplayer fullscreen - video slightly ahead
divx player - video significantly ahead
virtualdub - perfect
mplayer - perfect

johnny mnemonic (divx5 / mp3)
bsplayer fullscreen - video slightly ahead (was perfect in a couple of tests!)
bsplayer windowed - video slightly ahead
mplayer fullscreen - perfect
mplayer windowed - perfect
virtualdub - perfect
media player - video very slightly ahead (less delay than bsplayer)

pirates of the caribbean (divx5 / ac3)
bsplayer fullscreen - video slightly ahead
bsplayer windowed - video slightly ahead
virtualdub - perfect

Each time, MPlayer (linux mplayer ported to windows) and VirtualDub played the files perfectly without any delay at all, while BSPlayer, Windows Media Player, and the DivX player all played the files with video slightly ahead of audio.

Is it possible that MPlayer and VirtualDub sync up the audio using a sync value specified in the avi? I know that such a thing exists, but do the other three players ignore it?

I've looked through this forum and couldn't find any suggestions that help the problem. I turned post processing and film effects OFF in the DivX setup, and that didn't effect the sync at all.