I have an 08 Mac Pro with a stock apple raid card. 4 2TB WD Green drives make up the raid and I use it for my iTunes library and Aperture Library. I use the extra sata port for my 1 TB Hitachi boot drive which is the one I purchased my Mac Pro with. I have had this setup for nearly if not over a year with no trouble until the past week and a half. The raid utility shows that everything is fine. The battery is good, the raid partition is good, and even when I click through the individual drives in their respective bays it says SMART Verified Status Good. My trouble is this. Anytime I play a song or a tv show, or access files even without using iTunes the computer freezes. I can't click on anything, there is no spinning wheel and I have to manually restart it. When I do restart it the raid volume does not show up in the finder. But when I go to verify disk or repair disk in the disk utility it shows everything is fine. I have to rebuild the volume with diskwarrior and when I use any file off of the volume it freezes. I've replaced the drives and that hasn't helped. So I'm at a loss here. Any help would be appreciated.