I'd suggest deleting any extension, application, preference file containing the name 'airport'. Set the extension set to "MacOS All" extension set and reboot.
But
BEFORE you do that, grab the 2.0.4 Airport installer from here:
http://download.info.apple.com/Appl...-Communications/AirPort/AirPort_2.0.4.smi.bin
Old Apple download page archived (Download itself is missing):
https://web.archive.org/web/20111011141917/http://support.apple.com/kb/DL1154?viewlocale=en_US
After re-installing, make sure the airport extensions are enabled in extension manager and reboot.
If that doesn't work, I'd try a power manager reset:
https://support.apple.com/en-us/HT1431 - Scroll down to "
Original "flavored" iBook and iBook (FireWire) computers" for directions
Note that after the PMU reset, your date & time will be reverted to 1904