You cannot cold boot from the PCI card in the Mediator; further speculation is lofty mental fellatio, but you can boot from a CF/SD card to the point the PCI card is initialized and them continue on from it; a warm boot could be arranged (easily in OS 4.1) but more difficult in OS 3.X without the initial boot.
Best yet is to fix the SCSI issue! Can you be more explicit than "flakey?" Could it just be a termination issue?