My Radeon 9700 Pro started to show memory errors so I swapped in my BFG 7800GS OC card as its better for DX9 games anyway. Everything will boot just through the XP splash screen, but when it gets to the "Windows is about to start" or whatever screen just before the user account selection screen, the screen blanks out. The monitor doesn't go into its no signal mode, it's just a black screen.

At first I thought it was a case of the PSU not giving enough juice to the card, so I swapped it out with the most powerful unit I had, a 500w unit with 28A on the 12V rail. It still does the same thing with the new psu. Googling suggests a psu with at least 400w and 22A on the 12v rail.

Under safe mode the display is just fine, I can futz around, tried uninstalling and reinstalling drivers, etc. I'm currently at 307.something for drivers btw.

I even tried a linux live cd and everything works just fine. I'm lost here. I was right in the middle of another run through KOTOR when the VPU Recover errors started popping up left and right signalling the bad memory issue on the radeon.

Anyone have any suggestions?