Ok, my problem is that I am trying to multiplex the video (divx) and audio (wav) in Virtual Dub on my new machine, and it gets to about 10% and just stops working. VirtualDub is still clocking up time, but no longer processes anything. VirtualDub happily encodes my d2v files to divx on this machine, and is only giving me trouble when I try to combine the streams. No what really confuses me, is that this never happened on my old (slower) machine, and I'm using exactly the same version of VirtualDub, installed from the same CD. I'd really appreciate any light anyone can shed on this for me.
Well I managed to solve my own problem, and thought I would share this, as I see others have had this problem, and have not found a solution. It seems that the reason I could no longer multiplex was because of a conflict that was occuring, but was not presenting itself. I've traced the conflict to one of the audio programs that ship with the Creative Soundlabs 5.1 cards, it installs an MP3 codec which somehow interferes with VirtualDubs ability to work with MP3 codecs installed. This of course allowed versions that used to work to start playing up. So if anyone else out there upgrades their machine, or gets a new machine, and can't work out why they can no longer encode, then perhaps you could also have a hidden conflict with something on your new machine.