Endlessly "acquiring network address" in guest OS

Hi,

I was on a bridged-ethernet connection with a fixed IP for a long time. Using OS X as host, windows XP SP3 as guest, the latest version of Parallels 4. I started telecommuting and need for it to be DHCP now, so I switched to DHCP in windows, and now the network connection says "acquiring network address" endlessly. It seems to be some problem with the virtual network card in parallels on the mac side or maybe the DHCP server mac side OR I have some problem in XP that's preventing this. What I have tried:

uninstalling parallels entirely, reinstalling
importing into trial version of VM Fusion, exact same problem (which tells me it's an issue with the VM version of XP)
uninstalling parallels tools and reinstalling
deleting and re-adding network card from parallels configuration.
shared networking, with XP set to DHCP
bridged networking with XP set to DHCP
shared networking with XP set to specific IP in the range that the parallels network adapter would assign it if they could talk to each other (which worked! made a connection, but since I didn't know what to put for gateway, couldn't go anywhere)
host only, with mac os x internet sharing to the host only en3 network port.
going to devices in XP and deleting ghost tabs (from me uninstalling the network card a few times on XP side)

The two parallels adapter ports in mac network settings are green. the prsl_natd or whatever seems to be running. Any other thoughts on what I need to do in XP or Mac or Parallels for DHCP to work? Being stuck on "acquiring network address" endlessly tells me there's a basic disconnect somewhere. I would prefer not to just reinstall XP from scratch, but it looks like that's where I'm heading. Any other things to try would be appreciated. Especially things in XP I could do to start the networking over from scratch. Is there something else to change in XP if it was used to being a static IP other than to tell the tcp/ip to use DHCP automatically?

Hauss