Find out the power rating of ALL PCI cards installed,you may need to lower transfer rate of SCSI card as suggested, although I can almost be certain that the power of cards is not matched and therefore may not be supported configuration under logic board that your using( unfortunately limited to factory specs). Check Apple Tech Info Library or the 8600 manual it is in there, it gives best usage of PCI logic board bus power. I know that in my G4 400, 001 and a SCSI 2940 eats most of avail power leaving my capture card almost permanently in a static bag. Would be nice if PCI support was taken alittle more seriously by Apple considering they now claim to do Video(only DV) as a core market. And what a huge range of firewire audio and video interfaces there is.......