The solution, of course, was simple. I eventually took pity on the Sunrocket CSR and explained: you set up a fixed ip address on your machine, access the router switch to dhcp, go back and tell your tcpip connection to get an ip address from the dhcp server again, and then repair the connection in XP.
So now he's confused, and knows he's screwed up. Unfortunately SR has no system for escalating calls other than to send it to tech support. This was a call center in the Philipines...if you're lucky enough to get one here, you might have better luck.
Anyway, so he hangs up on me, on the pretense of transferring me directly to tech support, so they won't have to call me back. I call back again, and get a new breed of idiot, who makes me jump through the same hoops. I refuse halfway, and demand to speak to a supervisor. She says no. Reminding her that I work in internet marketing, have several blogs, and will share my experiences with the BBB, FCC, my organization (a network of community technology centers and advocates) and God, she changes her mind.