For some reason, whenever typing on my iBook's keyboard, the letters keyboard tiles I hit produce what they would in numlock - however, the numlock key is not lit. When I hit the numlock key nothing happens, no sound. However, I've hooked-up an external keyboard and typing works fine. If I hit numlock on my external keyboard my iBook produces a chirp sort of sound. Also of note, hitting the Apple/Command brings a prompt inquiring if I want to shutdown. Any way to remedy this?