PowerBook - Pismo Flashing ? Startup Problem

A few days ago my Pismo stopped working, or rather, it works, but refuses to start from my hard drive. I now get a flashing ? icon every time I turn it on. I though there was a problem with my hard drive, but after trying another one, the same problem persists. It stars from a bootable Norton Utilities cd, which gives me a message about the date being wrong... Is this something related to the pram battery? or is it more serious?
Your help is greatly appreciated.
Thanks.