Probs bsplayer and win xp

I've got a big problem with the latest bsplayer and win xp. everytime I open a video it works fine until I change to full screen playback. It is not watchabel because the motion is not smooth. There are short breaks every 3 or so seconds.
If I open the same file with windows mp it works excellent even in full screen. Does anybody have a suggestion?
Thanx!