3 display setup

I have been trying to setup a computer with 3 displays for a few days  now and am having nothing but troubles. I have run several different setups which I will explain now.

1. Asus p5gz-mx motherboard, Nvidia GeForce 8400 GS PCI-E card + ATI Radeon 7500 PCI card. Using Windows Vista Ultimate, installed all the proper drivers and I get an error shown in the device manager stating that windows has stopped the ATI card because it has reported errors. Ok.. Lets try matching video card manufacturors.

2. Asus p5gz-mx motherboard, Nvidia GeForce 8400 GS PCI-E card + Nvidia GeForce 5200 FX PCI card. Windows Vista gives the same error message for the PCI card. Ok... lets try something else...

3. Asus p5gz-mx motherboard, Nvidia GeForce 5200 FX PCI card + ATI Radeon 7500 PCI Card. Windows Vista again gives the error message for the ATI card.

4. Gigabyte GA-8S648FX Motherboard Nvidia Quadro AGP card + Nvidia GeForce 5200 FX PCI card. Windows XP Professional, both cards showed in device manager and all 3 monitors showed in display manager. Tried to extend desktop from display 1 to displace 2-3 and computer locked. Installed Win2k pro for kicks, as I did a setup like this several years ago using two pci cards and windows 2000 pro, with no problems.

The only scenario I have not tried is using both the PCI cards in the Gigabyte board. Does anyone have any suggestions. Hopefully there is something obvious I am missing. $400 for a quad vga video card is a tad rediculous... As far as I can tell jumper settings are correct. the only mention in the manual for the Asus board is to set the jumpers for PCI-E instead of onboard video....