I've run into a small dilemma on my iBook G4. Every time the system either reboots with the adapter plugged in or looses power when I disconnect it, when I turn it back on, it says that none of the preferred networks are available, even though my network shows up on the list. I check Network Prefs. and it has my network in there with the correct password. Here are network and system specs:

3 AirPort Extremes, 1 Express (1 Extreme is the main router, Express and 2 Extremes are network extenders)

Broadcasts 2 networks, a 2.4GHz (for the iBook) and 5.0GHz (for my Intel machines)

WPA2 Personal password

1.42GHz iBook G4 14"

512MB of RAM

Integrated AirPort Extreme card

Running 10.5 Leopard