wow. lost another million hairs over this one.
Installing the new driver for the new kernel wasn't the problem. Sure, it would have been better if I had remembered to download the headers before
I lost network, but I had another machine I could use. The problem was: everything installed and configured perfectly, yet I had no signal.
The problem was this: my wireless network has no wep key. I set it up that way specifically because I didn't want to deal with auth problems. I guess these things expect to have that key by default, and nothing tells you the key failed, or that its not needed. There's also no option in the gnome network settings to disable it. I finally got to the iwconfig man page and tried a few things. There was finally a magic incantation:
iwconfig eth1 key off
and the signal instantly came on. Sheesh.