I've recently been trying to put together a DVD that will merge an avi video file i have (converted of course) with a commentary mp3 file. What I would really like to do is create a DVD that has 2 audio tracks the user can switch back and forth from: one track with the regular audio and another track with the commentary playing over the original audio. I think I've figured out how to merge the commentary and original audio (using Audacity works fine) and also how to convert the mp3's to .ac3's. The problem I am facing is that I can't seem to get the program I am using (DVD Author) to allow me to have 2 tracks with the .mv2 file I've selected. Can anyone help me out along those lines? Another question I have is whether you guess think that TMpgEnc is better to use than any other encoding program. I hear that Cinema Craft Encoder works well but have yet to really toy with that program. Any ideas? Thanks!