Hi all. I wonder if you guys could help me out here? First, the Mac Pro's specs: - 2x2.8GHz Early 2008 - 4 SATA-II HDD drive bays containing: + Bay 1: OS X, 500GB Western Digital WD5000AAKS (Apple-supplied) + Bay 2: Data, 500GB Western Digital WD5000AAKS (Sep 2007) + Bay 3: Stuff, 1.5TB Seagate ST31500341AS + Bay 4: Projects, 750GB Samsung HD753LJ The problem I'm experiencing is that the Data drive in Bay 2 is no longer mounting on startup. It doesn't even show as a drive in Disk Utility. I've moved the drive to a different bay and it will mount on bootup about 20% of the time. If I put Projects or Stuff into Bay 2, they work fine, so it's not the bay itself. I ran the Apple Hardware Test's extended tests and looped them overnight, but it reported "No trouble found". Sometimes, Apple System Profiler reports, "There was an error while scanning for Serial-ATA devices". Running a disk check on Data when it does mount yields no problems, so the data's fine (and it's backed-up anyway). I needed a larger drive so got a 2TB Hitachi. The Mac Pro isn't recognising it anywhere. It's not there in Disk Utility. The Finder doesn't tell me I've inserted a disk that OS X can't recognise, etc. Apple hasn't updated the specs for the Early 2008 to state that it can handle a 2TB drive (as 1TB's were the only ones available in early 2008), which isn't a problem because Google yields lots of results with people using 2TB drives perfectly well. I've tried the drive in all four bays and it is never recognised. I'm getting really annoyed with this now, as all my music is on the Data drive and I can't do anything in iTunes anymore. (Not the biggest problem, but one of the main ones...) I don't want to sound desperate, but please help!