Booting from WDS Server

[beardy]

I have a Dell Precision T3500 workstation that I'm using to build sysprep images for my organization. I'd really like to use VirtualBox to manage my VMs, but I can't seem to get PXE boot working properly with my WDS server. This is necessary for testing purposes.

The VM boots, gets a DHCP address and begins the WDS boot process. I select the appropriate WinPE boot image and then the screen goes blank. I think it may be booting, but incredibly slowly. I have left it for an hour but the usual progress bar hadn't even appeared by then!

Here are the details:
Dell Precision T3500 Workstation
Xeon W3520, 12GB RAM
Windows Server 2008 Datacenter
VirtualBox fresh install today with "VirtualBox-3.0.4-50677-Win.exe"

I'm using the Intel PRO/1000 T adapter, but I've tried all the options. The AMD-based adapters give a TFTP failure.

Any advice much appreciated!

[vbox4me2]

NAT or Bridged?