Not sure what happened, but my AVI2DVD stopped working. After joining the AVI files, it just popped out "Interface Not Supported" when it is time to demux the sound. I searched for this error, but it's not anywhere in the forum, and the only reference I got on Google was for some rare Delphi error (I can see that this program was written in Delphi, but that fix didn't work for me).

So, I reinstalled AVI2DVD, and it worked this time! (Of course, I have to pull in the joined AVI instead of the two separate pieces).

Thus, your lesson for the day: when you got an error in the app that was working before, before you starting changing your config and update DLLs and such, try just reinstall the app itself. It MAY save you a lot of grief.