It's a dual head card: VGA and DVI (and S-Video too)
Running in XP, it was happily running two monitors, a 22" Acer and a 26" LCD TV.
Then I rebooted into Linux, and it was cloning the display instead. Fine. I booted back into Windows XP, and the displays were cloned until the point where it showed the Windows XP splash screen. After that, the DVI output stops providing a signal, and the Acer monitor just goes blank.
In Display Properties > Settings, I try to enable the 2nd display as usual. The 2nd monitor shows as greyed out, so I enable "Extend my desktop onto this monitor", click "Apply" and nothing happens except that the checkmark disappears and the 2nd display is greyed out again. The first time I do this it gives me the 15 second message if I want to keep the new display settings, but after that that it does nothing except remove the checkmark.
I've also tried enabling and making the 2nd display the primary display, but that just reverts too. Looking around in the advanced ATI settings got me nowhere too.
Is it possible that booting into Linux made some change to the Video card?
I'm normally the guy that everyone asks for help with their PC, but I'm stumped and about to order a new video card!