Some things I found while surfing around on the 525M laptops in general:

* nVidia CP -> Manage 3D Settings -> Global Settings -> "High Performance nVidia Processor" (if you haven't already)
* Folks report issues with the 290.xx series drivers but not with the 285.62 WHQL. That might have been resolved in the 295.xx series that's available now.
* Try removing the NVidia drivers, reinstall them with the "clean" option to clear out any cruft in there.
* Verify your BIOS settings specify the NVidia GPU and not the onboard Intel.

Good luck.