Video Playback Freeze

[darktubbly]

This one has been bugging me for quite a while now and I've finally gotten ticked off enough to actively do something about it. Video playback of any DivX, XviD, and QuickTime files results in an intermittent 10-20 second freeze at random points in the video while the audio continues. MPEG's and ASF's work fine. I don't think it's a hardware/overheating problemt because everything works fine when I try it under Linux. This never used to happen before and I've tried everything, save reformatting. I've tried reseating cards, trying other media players, turning down graphics/sound acceleration, etc. Any help would be greatly appreciated!