I've been messing around since release day trying to get this game stable, tried several drivers and with a LOT pf perseverence have it running nice and smooth on a 7800GT, I'm using these 94.20 drivers.
Triple buffering seems unavailable for some reason in the control panel so against my usual preference I have disabled v-sync, due to the frame rates being under my refresh rate 85Hz I rarely get any tearing except for when I collide with a lampost or building, in my opinion if I do that then I deserve a little visual discomfort.
edit-the performance with these drivers is better than any other I've tried and that is without any overclocking
Not sure what card you have but my lockups have ceaed since using these drivers. If it's an ATI card then I have no advise. Sorry.
What is the screenshot key or is everyone using fraps or similar?