Vista - Vista 64 w/ Radeon 9550 AGP and Radeon X1300 PCI

I've been trying like crazy to get my 2 video cards to work in Vista. I originally had a 9550 Pro 256 that works beautifully, but I needed to add another 2 monitors so I added a Radeon X1300 PCI card. But whenever I enable the PCI card monitors in Display Settings, either the system runs like garbage (almost as if I was trying to run on a Pentium II, yes its just that bad). The rest of the time the driver keeps crashing and Vista recovers and then immediately crashes again and keeps going until I turn it off and reboot with the PCI card disabled.

I have installed the latest ATI 7.3 drivers, I have installed the latest chipset and other drivers (at least all I could find, FoxConn doesn't have any 64 bit drivers on their site) I even tried a format and reinstalled without the CCC to see if that made a difference, but nope.

I have gone into my bios and set it to set the IRQ, i've tried letting the OS, I've set the PCI to the primary, then the AGP to primary, I've looked for updated BIOS but I already have the latest and have checked and tried every setting in the BIOS.

Anyone have an experience like this? Any ideas?

Here's my hardware:

Motherboard: FoxCon K8S755A-6EKRS (http://www.foxconnchannel.com/EN-US/Product/motherboard_detail.aspx?id=en-gb0000030)
Processor: AMD Athlon 64 3200+
RAM: 2 GB DDR400
Video: AGP = Radeon 9550 256 MB; PCI = VisionTek Radeon X1300 256 MB
Hard Drive: WD 160 GB SATA, WD 250 GB IDE
CD: Sony DVD-RW and Sony DVD-ROM

However, the system runs absolutely beautifully with both cards enabled under XP 64.

No ideas? Anyone? Anyone at all?

Thanks.