I recently purchased an OWC Mercury Elite Pro Qx2 enclosure, with 4x1TB drives in RAID 5, for use with my MacPro1,1 [OS X 10.6.8]. The unit works correctly when connected via Firewire, but when I connect it via eSATA to the internal ODD SATA ports [using the Newertech adapter cable], I find that the machine hangs. Access to the drive blocks after just a few accesses. I have verified that the external drive is powered on and operational before starting up the Mac Pro -- so I know this is not about the lack of hot-plug ability on the ODD SATA ports. I have also checked with another eSATA capable drive [a LaCie d2 Quadra], and encounter the same issue -- so I don't think this is actually related specifically to the OWC enclosure, but rather related in some way to the ODD SATA ports themselves. Does anyone out there have a similar configuration? Is anyone else encountering similar difficulty using the ODD SATA ports? Spidey!!!