I had this issue too and fixed it by updating the driver for the graphics card as described above. But, I ran into another problem: When I set "Use all displays in full screen" and use 2 monitors in full screen, the mouse pointer position is "calculated wrong", so that the mouse is pointing 1/2 the length from the left end of the left monitor. If I use 3 monitors, the mouse pointer position is 1/3 of the length from the left end of the left monitor. This only happens in full screen mode, if I stretch the VM window over all screens it works perfectly.
EDIT: I found the solution to this problem. It was basically the same problem as with the Graphics adapter. It was the mouse drivers that had been reset to windows defaults. I updated them all (both PS/2 and HID mouses) with the drivers in the C:\Program Files <or Program Files (x86) for 64-bit Windows>\Parallels\Parallels Tools\Drivers\prl_mouf folder and then it worked perfectly.
Last edited: Oct 19, 2013