Well, I think I finally got the codecs unsnarled. I did a meticulous uninstall of every codec I could find on my machine, until none of the DivX files played at all. I started from scratch with DivX 3.11a then added DivX 4.11, DivX 5, and all of the audio codecs (and only the audio codecs) from the Nimo pack. Everything seems to play normally now. Thanks for the suggestions, everyone!
Juliet
