It's PCMCIA. I can get it to work on Ubuntu by going into the manual network configuration dialog, turning off roaming mode, and making sure it gets its address from DHCP. There doesn't seem to be any obvious way of making it connect automatically on startup; it seems to *require* the dialog box.

Windows is even weirder -- it's worked once or twice, but most of the time it doesn't. It claims to be connected, but you can't actually get packets through.