I am setting up hard drives in a new MAC Pro 2008 octocore. I have installed 3 x 1TB WD Black drives in bays 2, 3 & 4. The ones in bays 3 & 4 are fine. The drive in bay 2 installed OK but next day had disappeared from the desktop. I fired up disk utility which recognised that a device was present but it was not recognised as a WD drive. Instead, it just said "media" with capacity of 0 bytes. I sent the WD drive back to the supplier who gave me a replacement. I installed that in bay 2 & exactly the same thing happened. I tried the dead drive in an external USB case & had the same. I also tried it on a PC which crashed on boot. i got on to Applecare who said that I had either 2 bad drives (pretty unlikely) or a dodgy bay 2 socket & I should try another drive ($160 a time - great!). With some trepidation, I moved one of my good HDs into bay 2 as a test & it's been running OK for 3 days which suggests that the socket is OK. Would appreciate any bright ideas as two consecutive HD failures seems unlikely.