OT: Startup problems

[Dean]

Hi All

Any ideas why my new Pismo 500Mhz will start up fine
from a cold start, but when I try to do a restart, it cant find a disk.
Again, it starts up fine if you shut it down all the way.
I've reset the PRAM, disconnected the batteries for 4 hours at a time,
tried a different hard drive, removed the memory one stick at a time,
reseated everything at least once. It has boot rom 4.1.8 installed.
This will do it if I boot to OS 10.2, 10.2.3, 9.2.2, or 9.1. theres no 
difference. Oh and it will always start and reboot from the dvd drive.
Also, when I do a restart the hard drive spins down and wont spin back up.

HELP !!!!

Dean