well that seems to have fixed it. i uninstalled xvid completely and reinstalled. reinstalling over it didn't work. but after your post i decided to give it another shot. seems perfectly fine now. probably just a matter of the videos being encoded with a newer version than my decoder. xvid has always been a bit flaky with using older versions to play video encoded with a newer version. never had it cause such a big problem before though.

baka - go into add/remove programs and remove any entries for xvid. then make sure the xvid folder is gone. after that download the latest version and install that. hopefully that will work for you as well.