On this system:
QDI Advance 12 board with Apollo Pro266
Pentium III-S 1.4GHz @ 1.59GHz
2 gig RAM, and an A-I-W X800XT

With this PC, I find that just as one problem's solved, another one comes up...

The previous "blockiness whenever I close a window" problem is solved...here's a new one for you guys.

You know how computing.net and some other sites have green advertising links all over the place? If I run the system above with Win XP and an X800XT video card, the entire system crashes and reboots whenever I move the mouse over one of these green links. Strangely, Windows Vista doesn't seem to be affected and is fine with the X800XT.

I don't want to run Vista permanently just yet. The only way to get XP running stably is to replace the X800XT with a 9800Pro. Why does the PC do this, and how can I fix it? The PSU is an Antec 380 with 24a on the 12v line.

Have you tried reducing the CPU overclock? I doubt there's an AGP/PCI lock in the BIOS, so you're pushing the limit there. And it seems to me the X800XT is too much card for that setup anyway...the 9800Pro is more in line with the rest of the hardware. The P3 gets all it's power from the +5v rail, not the +12v, so 24A on the +12v isn't an issue. Try backing off the FSB to about 140MHz & see if that makes any difference.

I set the FSB to 140MHz, and now all of my USB devices work properly! w00t!

But still no luck with the X800XT under WinXP.