I had a Radeon HD2600 XT and it was NOT compatible with Windows 7. The strangest problem I've seen yet. Any large file transfers caused a BSOD. Multiple installs, clean or upgrade, 32 or 64 bit, and different versions of display drivers. All those combinations caused a BSOD with my graphics card.
This has happened since day 1 of Windows 7 being publicly released.
I figured it out by putting an old ATI 6800 card back in that I had removed when I finally installed Vista SP1. All file transfers worked perfect and Acronis worked as normal. Windows 7 worked perfect except for Aero and my Graphics Score was at 2.0
I upgraded to an ATI HD4830 and all is working perfect.
I'm on 7137 and would be on 7201 if Microsoft hadn't screwed up compatibility with Acronis Backup!