My mac (iBook G4) has been out of commission for awhile, because after downloading an update (using the OS automatic update system) it lost the ability to reboot.
At first, it got stuck on the apple loading screen. In verbose mode, it gave me a message along the lines of "Failed to connect to window server" over and over again. I tried using the OS disc provided when i bought the mac, and i get a "Unexpected Error, We are panicking" message and it stops. I ran the hardware check disc and everything seems ok.
A few months later (today), i started getting a flashing globe and a question mark before i even get to the apple loading screen. I tried holding option on startup and it sees the drive, but i can't select it.