Hi i am attempting to remove a secondary audio stream from an XviD movie, whatever i do it seems to mess up the sync horribly in the movie

i load the movie in virtualdubmod, it gives me a notice about a VBR audio stream and how it will introduce some amount of skew

i go to the audio stream section and disable the audio track i do not want, and save my avi, the sync is just horribly off

i want to remove the commentary stream as it is a waste of space and also windows media player likes to play both streams at the same time when i watch the movie

does anyone know what i can do? besides re-encoding anything, thanks