videos not working vistax64 build 5384

I have a radeon x850xt which seems to be working perfectly with ati's 5/23 catalyst drivers. Though it does not show the 3d preview which it says is disabled? I have aero working, i think, as all my winows are clear when windowed. The cataltyst software identifies my card properly as does vista. However, when i went through the media center set-up, the video that is played looked terrible, it seemes whenever there was motion the video became garbeled and became grey where the motion occured. Also, media player fails to generate thumbnails when i look at the video files, and crashes when i try to play one.. (crashes after a period of time, it still responds at first and will close however it remains in the task manager even though the program is no longer displayed. I didn't think it was the drivers, but tried the native ones with no change. Anyone else have this kind of problem?