2 T-Kimura :
6x.xx drivers are optimised for the gf series... it could solve problems on old gfx card but it's not the priority of nvidia developpers, their priority is to optimise and debug their driver for the new instructions providing with the latest gfx card, refraction has said that these drivers are unified, well it's true... but it should not slowdown the process on older card like he said... in fact, the gpu of the gfx card work like the cpu, i mean there is instructions set like a cpu, and these instructions are the same on all cards (with add-on on the new ones, of course...), so it's not a question of optimisation for a specific card... using the latest driver should be the best choice in most case... but it doesn't mean it will solve the existing problems... sometimes on the contrary it generate new problems...
2 zherow :
have you make a try with the 6x.xx beta driver ? because i have said that the priority of the developpers is the news instructions set, but they also update their driver for the "older" gpu instructions when they have time... you should try, in the worst case you can return to your 45.23 driver...