Going into Network Diagnostics to connect didn't give me any more options for password type. There was just a field for a password, no indication that it was WPA Personal. The password didn't work there.
I set up two locations and switched between them, but the password was not accepted in either.
Removing AirPort passwords from my keychain and rebooting didn't change anything. Since I haven't been able to connect to the network even once, there's nothing stored in the keychain for it anyway.
Turning the modem and router off and on didn't work.
I also tried going to 192.168.0.1 on a housemate's computer, to see if I could influence the router that way. I got a login screen on which the network password didn't work.
I'm starting to think the solution is going to need to come from some understanding of what specifically is stopping my computer from connecting, rather than my standard (and usually sufficient) approach of changing minor things back and forth until it mysteriously starts working.
The password I've been trying works for the other computers in the house. It fails for mine as though I'd entered the wrong password. Maybe there's some difference in how Windows and OS X send passwords to routers? If so, is there a setting I can change to mimic the behavior of Windows?
I've read reports of people having similar problems with WEP networks, which were solved by putting a dollar sign in front of the password. This network uses WPA, not WEP, but I tried this anyway. It didn't work. Is there another trick along these lines that would work here? And why does the dollar sign thing work in any setup?
Basically, I'm curious why the same password would yield such different behavior on different computers. Without prolonged Internet access, my ability to look into this is impaired. Anyone know what the deal is or might be?