Issue with powering on MBP with external drives attached

As the title says, I am having a strange issue with powering up my MBP with my external drives attached.

Info about my equipment:

Mac:
Mid 2010 17" MBP
2.66 GHz Intel Core i7
8 GB 1067 MHz DDR3
OS X 10.8.2

Drives:
Main: OWC Mercury 6TB Array formated to RAID 5
Backup: G-Tech G-Raid 6TB formated to RAID 0

Connectivity:
eSata via Sonnet Tempo SATA Pro 6Gb ExpressCard/34


I believe it might have something to do with the Tempo Card because I just recently bought the Pro version after my old non pro version died on me, and it just started happening once I got the new card.

It also might have to do with my power up procedure.

I start by turning on the Drives first and let them get up to speed to a "ready state". Then I turn on my Mac.

I do it this way because I think that if the drives are at that "ready state", it's easier for the mac to detect it? Is there any validity to that theory?

I've done this with no issues for years. But recently, (after I replaced the Tempo Card) after the drives are up to speed and I turn on my Mac it makes that first sound like it's turning on and then it stops.

If I unplug the Tempo card, I can turn on the Mac with no issues. And once I'm on the desktop I can plug the card back in and all the drives pop up and everything seems to run normally.

Any idea why it would be doing this?

 

That actually makes a lot of sense.

I made a 500GB partition on the G-RAID as a back up for my Mac HD.

So it would make sense that it was getting confused because there were two drives with the exact same info on it, including OS system files.

I designated the drive like you said and we'll see if that helps.

Thanks for your help Ledgem!