I'm still not sure what went wrong, but I decided it was time for a little head banging until I figured it out.

The last thing I did was down the network services and unload the ne2k-pci module (have a Winbond W89C940 card), then reloaded the module and restarted networking and it got the right IP address - I'm posting from my Knoppix box right now.

Okay, so now I have a solution, but I'm not sure I understand the problem. The ne2k-cpi module was loaded, as it should have been, but it almost seems like networking was being brought up before the module was loaded (although modconf shows it installed in the kernel).

I guess I'll see on the next reboot if it stays straight or goes south again. At least for the moment I'm back online.