Emax

Has anyone had the same experience...
I eventually managed to find the right CF cards for both my Emax II's (1Gb, Calumet branded). After a few months, I managed to get hold of another ACARD and IDE-CF adaptor. I 'thought' it would be easy enough to install a second CF card (with a different SCSI ID number) in one of the Emax II's. Everything seemed fine - SCSI cable, Molex cables, jumper settings checked on both ACARDs, Master and Slave jumpers set on the IDE-CF adaptors...
But on powering up, the PSU started clicking and I've managed to literally fry one of the CF cards (the primary / master boot card). I will now carefully check both the IDE-CF adaptor and ACARD on a PC, to check for any damage.
I can only think that a 12V and a 5V rail may have crossed over somewhere, but I couldn't see this when checking the cabling. 
Anyone had the same issue? or successfully ran with 2 separate ACARDs and CF's in one Emax II??