PCI standard PCI-to-PCI bridge problems

Hey all,

I've been trying to migrate my machine at work to Win 2008 Server R2 64-bit and am having some trouble getting a PCI graphics adapter working. Regardless of which PCI slot I plug the card into, I see a resource problem in Device Manager indicating either a "The device cannot start. (Code 10)" or "The device cannot find enough free resources to use... (Code 12)" issue with the PCI standard PCI-to-PCI bridge component. I have tried modifying IRQ assignments in the BIOS to ensure no conflicts, but nothing seems to help. Here's the system configuration:

Dell PowerEdge 840, A05 Bios
Dell Perc 5/i RAID Controller + 4-disk Raid-0 array
Onboard Broadcom NetXtreme Gigabit Ethernet
Matrox Millenium P690 PCI graphics adapter
Windows Server 2008 R2 Enterprise 64-bit

The same hardware configuration was working fine on Windows Server 2003 Enterprise SP2, so I'm assuming this is some sort of bug with the PCI driver for 2008. I really need to get this issue resolved, so if anyone has any suggestions I'd appreciate it. Thanks!