169.254 IP nightmare on XP

[temponed]

So I read a bit of the existing post on here - the "169 Nightmare on Vista" but as the particulars of XP and my situation may be significantly different I figured I would put my problem out there and see if anyone can shed some light or offer some alternate approaches.

I recently lost my network connectivity and began getting the fabled 169.254.xx IP address.

Details of my set-up. My machine is running XP. I am going directly from my NIC to the modem supplied by my ISP which is Comcast, running the McAfee security suite for Comcast.

Things I have tried to resolve the problem:

having Comcast reset the modem;
power cycling the modem
releasing and renewing the IP address
had a tech from Comcast come and replace the modem and the ethernet cord. He told me it looked like my NIC was shot so I purchased a new one and installed it in an open PCI slot. It installed fine but still only got the 169 address. Read on some post that switching the NIC to a different PCI slot worked so I tried that. It did not work.
Spoke with the folks at McAfee who instructed me to boot in safe mode with McAfee disabled to see if McAfee was the cause and it was not.
Ran both Winsock and LSPfixes. (Not being super savvy I don't actually know what these things are but I saw them on forums as potential causes; the LSP fix program did not detect any issues. the Winsock reset ran but did not fix the problem)

I am more or less at a loss at this point. Is re-installing Windows my only hope at this point?

One thing I have not tried but will try tonight is testing another computer through the modem. Hopefully this will shed some light on whether it is my computer or a problem with Comcast.

thanks all