I poked around with my wireless some more tonight, being as how I've mellowed out some. Card was using the most recent drivers and utilities. Network was working fine. Hmm.
*poke poke poke*
Well what have we here? Windows managed to turn on its firewall! Oh goody! Why on earth do I need a software firewall when I have a perfectly good hardware firewall sitting over there on my desk?
I turn off the firewall. Magically, my wireless connects.
Fuck you, Windows.