Hi Xzoltan,
Unfortunately, the beta drivers did not help. At this point, I would suggest you try to revert to an older version of the drivers. It seems people on the interwebs have been having the same error with their graphics card and for some, reverting to the previous version of the whql driver helped.
I'd like to suggest one more thing, I know you have already tried and lower your graphics settings and the result was not promising. However, did you try to change the cursor to System cursor in the graphics settings? For some very odd reasons, I have read on this forum it had helped some people having issues with drivers... I think you should definitely give it a try too, if you haven't yet. Also, does running the game in windowed mode changes the behaviour in any way? If you haven't tried this yet, it would be worth a try too.
And that is one long shot, but I think if your computer is so you can open it (without voiding guarantee), you should double check the graphics card is not badly pinned by removing it entirely from its slot, blow the potential dust on it and put it back. The error you see can be an hardware malfunction caused by some "misplaced dust".
Cheers,
/D
I will give it a try, thank you.
I have tried the system curser thingy, no help. I believe I've tried the windowed mode as well, but I'll try again just to make sure. And, I will also check that there is no dust etc, and try reverting to older drivers.
I will let you know how it works out.