Hello!  Any help greatly appreciated!

I have a problem getting my computer to recognize a Lacie Quadra D2 external hard drive.  I'm running Pro Tools 9 on an iMac, Snow Leopard 10.6.7 with a Fireface 800.  My old Lacie Quadra D2 drive is recognized just fine.  When I boot everything (iMac, Fireface 800, Lacie drive) up with it, it shows up on my desktop, finder, and disk utility, so I know the cabling and power supply, etc. are all fine.

When I replace the original (now full) Lacie Quadra D2 with a new, empty, Lacie Quadra D2, hooked up the same way, it does not show up on desktop, finder, or disk utility, nor does it spin up.

BUT if I connect the new, empty, Quadra D2 directly to the iMac via firewire 800, bypassing the Fireface, it shows up just fine.  It's there on desktop, finder, disk utility, and I can transfer files onto and off of it.

SO, I know the system is set up properly, all cables work and Lacie drive works on its own.

I'm not super techie, so a little stumped.  Is it possible one of the Lacie Quadra D2s is a different generation and requires a diff driver or something?

Suggestions?

Full system details:
Imac running OS X 10.6.7
Memory: 8 GB 1333 MHz DDR3
Intel Core i7
Fireface settings version 2.91
Unit #4A997643 version v2.77
Kernel driver v2.91
Lacie Quadra D2 external 7200 rpm drive