Over in this thread I posted up the details on my current system. This motherboard has 2 onboard Intel 82575 EB Gigabit Lan adaptoers. I found one other thread where the poster had the 82575 and mentioned he 'fixed' his issues by getting a separate PCI NIC card, but I'd rather avoid that myself since I've already got 2 good Lan ports onboard. The device id in windows shows:
PCI\VEN_8086&DEV_10A7&SUBSYS_10A715D9&REV_02\4&187919FE&0&00E0

which means in the .plist the correct string would be 0x10A78086. For my previous Intel NICs I've gotten them to work by editing IONetworkingFamily.kext/Contents/PlugIns/AppleIntel8255x.kext/Contents/Info.plist and adding their device id's, but that didn't work this time. So...

any ideas?

hi, i've got the same issue as you've got.
the only solution i've found so far is to get a cheap compatible nic, but it _sure_ would be nice to be able to use this very nice & high quality network card... much looking forward for a fix for this...

Well, I have several older Intel pro/100's lying around and I had one in use for a while. The problem I had with that was some sort of ground loop, since I still use my gigabit adapter in WinXp/Vista/Debian/Ubuntu (this is a Xeon box and I have several others here). This is a small audio studio hence the ground loop issues cropping up, there are many cables here. Since I can't live with just a 10/100 card only I'm thinking about possibly getting the apple usb>ethernet adaptor or something similar.

Ok so I put an old PCI Intel pro100 into use until there's support for the Intel gigabit adapters...