Not sure if this is helpful to you, but I had a wifi issue last night as well. I had run airodump-ng earlier and failed to take wlan0 out of promiscuous mode, which drained the battery. I plugged into AC, booted it up, and the wireless util wouldn't find my AP. I rebooted (Power, "Switch off!"), but still no wireless connections were found. I ran "resetwlan", but still nothing. I looked at ifconfig in Xterm, and there was no wlan0 interface. "ifconfig wlan0 up" brought it back up, but as soon as I opened the wireless util to connect to my AP, it went back down.

One or all of the following got me back up:
-uninstalled any wireless-related apps
-Xterm: sudo gainroot
-Xterm: reboot

I don't know why that worked, but it did.