Desktop 845EPI not stable with NVIDIA 5900 FX card

Good old Frys. Bought a P4 2.66GHz / Intel Desktop 845EPI bundle this
weekend to build a system for a relative. He chose an Asylum GeForce
FX 5900 128MB graphics card. It was rock-stable in VGA mode while I
loaded the O/S, but once I applied the NVIDIA-specific drivers, it
became extremely unstable. It will boot to Win2K, but almost any
interaction with the UI results in a freeze, where a band of color is
displayed at the top of the screen (usually purple with vertical
stripes) and that's it.

I have updated the mobo bios, the chipset drivers, and the latest
NVIDIA drivers. I tried adjusting the AGP aperature size from 64MB
(the default) to 128MB. No change. The NVIDIA card runs like a champ
in an old AMD box with all the drivers loaded.

I'd really like to make this fly... I used to support the motherboard
group at Intel in my past life, and still live and work just minutes
away...

Steve