extract the audio in virtual dub to a wav file. use a programm like headache to convert the audio to a stereo wav. then use virtual dub to merge the video from the one and the new stereo audio track. set video to direct stream. save as a new avi and now your old way of converting should do.
if not, go here: www.vcdhelp.com or doom9.org
jesus christ was a gangsta rapper. they killed him. he came back and made a platinum album.