Ok,
I upgraded the Bios and the Cat drivers to 5.11(the latest). Still the same problem.
The card has a powerplug, which was connected, plus a seperate fan, which was connected.
Upon startup, the windows screen is set to 640x480, automatically from my 1280x1024 resolution, which is garbled by vertical lines that display various graphical glitches.
This is windows xp home. All drivers are up to par. My 9800xt works, I pull it out, replace with X800 and the problems happen. I switch back, everything a-ok.