I recently moved from a Power Mac G5 to a mac pro and in general it has been a smooth transition. One frustration recently however has been using it with my Drobo. I had two 1.5TB drives in my Drobo with some data. I connected it using FW800 as usual and created a sparse image for my Time machine drive. The Drobo was soon getting full so I added another 1.5TB disk. At first I couldn't get this to be recognised in either bay 3 or 4 - it span up but the green light never came on. I tested the drive in a separate enclosure and found it worked fine. As a last resort I unplugged the Drobo from the power and when it started up the drive was recognised! The only problem now is I sleep my Mac Pro when not in use and although the Drobo will sleep fine whenever I wake my Mac the drives in the Drobo spin up - the green lights come on and then all the lights go out and it reboots itself. OS X then gives the device removal message as if I had pulled a cable. I had seen this once or twice on my G5 but figured out it was when the Drobo hadn't been accessed and the drives were spun down - when putting the G5 to sleep the Drobo would start spinning up the drives just as the computer went to sleep. I got around this problem by making sure I accessed the Drobo before choosing sleep so the drives were spinning. This doesn't seem to get around the problem on the Mac Pro a wake from sleep seems certain to cause a reboot of the Drobo. My guess is Time Machine is trying to access the Drobo within seconds and it isn't ready - unfortunately it doesn't handle this well at all.