V-Ray RT + GTX560 - which driver to use??

[minifig]

Hi! I put together a new Windows 7 Professional x64 (SP1) workstation and I can't get V-ray RT (2.00.02) to work in GPU mode with 3ds Max Design 2012 x64. In CPU mode it works just fine, but when I switch to OpenCL and press the ActiveShade button, activeshade window opens with the message "waiting for image data..." but no image appears. Instead of the common V-Ray command window a message "V-Ray Standalone has stopped working" pops, and I must close the render window. It doesn't crash Max or even the render dialog.

The graphics card in the system is a GTX560 2Gb. Currently I have driver 285.62 installed. I also tried installing a few older drivers without any success.

I have another workstation with almost the same HW/SW setup, except for the Quadro 600 graphics card with driver 266.35 It doesn't support the GTX560, and the oldest driver I can find/use is 275.33

It seems to me this is a driver issue, so any suggestion will be appreciated!