Gigalan Ethernet Problem with GA-KNXP

I can't boot Windows at all with the Hardware LAN enabled. Clean install of XP Pro, with the latest LAN drivers from Gigabyte installed (I think -- the procedure's a little confusing, but I installed the ProSet app from the XP32 folder).
The machine restarts as soon as it tries to load Windows.
With HW LAN disabled, everything's fine.
Using latest BIOS (F6, 8-18-03) and Fail-Safe defaults.
Any ideas?
TIA,
Will