nforce4 dfi ultra mobo networking controller 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.