Actually, you know, I just remembered the trick that I use. I knew that I replied to this thread because I had some sort of knowledge on the topic, but I somehow forgot to impart it.

If stuff is coming out clipped, try exporting just the audio to a separate WAV file (Export -> Audio) and use that audio track to author your eventual DVD with. If you name the video file and that audio file the same thing (i.e. Edit.avi and Edit.wav), you can use Media Player Classic to play back the video with the other audio track.

I don't know why exporting the audio as a file separate of the video works, it just has for me. So try that.