Nforce4 (DFI Ultra Mobo) Networking Controller problem DHCP.

I am using a DFI Nforce4 motherboard with the Nvidia Networking Controller
that is built into the motherboard. This board has a secondary ethernet
adaptor, Marvel Yukon GB Ethernet adaptor. With the Nforce controller I
cannot get an IP using DHCP with the beta 2 of Vista, however if I static an
IP it works fine - or if I enable the Marvel Yukon adaptor it can grab an IP
using DHCP. I would've thought someone would've reported this already as I
have a few friends with the same DFI Ultra-D motherboards that have the same
issue. I have no problems in Windows XP with either NIC using DHCP so it's a
driver issue with the onboard Nforce4 Networking Controller Driver in XP.

I have tried to update the chipset drivers for the board and the NIC drivers
with the beta vista drivers from Nvidia, unfortunately this doesn't resolve
it either.