Using WinMe and DivX5.2.1 with "Support Generic Mpeg-4" selected and a playlist with several types of avi files, e.g. .divx, .xvid and .dxgm (as well as some odd .mpg-files) no such problem here! (Like
Tizio reported.) So DivX-version (and/or OS) version seems to be of some significance. (To be sure I checked which filter used during playback of avi's: DivX!)