Definately run a NVRAM utility. After an extended period of dormancy my NVRAM settings got cleared. This caused the SCSI controller to be set to SCSI ID 0, which conflicted with one of the internal drives. This could be what you're experiencing.
EDIT:
IIRC, the defualt should be 7. I still haven't figured out why it was set to 0 in my case.
