I haven't ran 3DMark fully in a long time... the 12.xx series are best at the moment. Get the 12.41 WHQL drivers, they should be stable & fast.
I'm using 12.90 now and get a stupid dialog every time I boot. It says something about some missing entry in Nvqtwk.dll or somesuch dll. 12.60 didn't complain about that.
Ok, I just duplicated it with NVmax by clicking the "Load at Windows startup" checkbox in overclocking section.
Window caption is RUNDLL.
Text inside dialog:
Error in nvqtwk.dll
Missing Entry: NvHWCtl
It's the overclocking bit!