I have a geforce 3 ti200 on a sis 645 mobo. I am using detonator 40.72. Occasionally, the screen will lock and refresh, and then go back to normal. This gets annoying cause it happens often. I narrowed the problem to det 4 drivers on the sis chipset based mobo, but reverting back to older detonator drivers = slower performance and occasional bsod lock ups. Does anyone else have this problem? Thanks.