Apogee Duet + Macbook Pro = not working

So I just got my apogee duet (it's from 2007 which previously belonged to my friend who passed it on to me). I have a Macbook Pro 10.6.4 version and the cable it came with is a 400-400 so I went out and bought a 800-400 cable for it to plug into my macbook. Heres the problem, as soon as I plug the firewire cable into the port my macbook completely SHUTS OFF/CRASHES. EVERYTIME where I can't get the duet working. I tried turning off my macbook THEN plugging the firewire into the port. After that I'll turn on my macbook and it will work with the firewire plugged in but that does not mean I can get it working. The firewire has to be unplugged then plugged back into to initiate a response to turn the duet on but NO, my macbook completely shuts off again. I haven't even gotten a chance to use this baby, I haven't been able to get it working/turn on even once.

What is the problem here?!

I suspect your 2007 Duet is not compatible with your MBP. Why not get on their tech web site and ask? Here's the LINK. Notice the email support link on the bottom right.