In that thread, in the converting options. it was using Direct Stream Copy for the video stream. This means the source video is copied without converting. That method is fast but as it doesnt convert the video, the avi it creates might not play on the dvd player as well.
Since his player can play DivX, its best to convert the video to DivX instead of just using Directstream copy.
Virtualdub is a very good video tool for windows but its rather complex to use. You really need to know what you're doing to use its advance features.