Hey blink,
I have the exact same drive. I was allready using 5.1 when i got the drive. However i was experiancing alot of problems with this drive oustside of protools as well. I found the lacie firewire drives to be the problem. I searched out this application called "Heat utilities" It's a free download of their web site (
http://www.macpitstop.com/product-heat.lasso )Anyways, I now use their drivers instead of the lacie firewire drivers. Since then i haven't had a problem useing the drive with protools or otherwise. Hope this helps.