I have a pair of 500Gb western Digital My book firewire drives that I set up as Raid 1 on OS10.5. I am trying to use them on my new MacPro with OS10.6.6. I have downloaded the latest drive manager from Western Digital but they are not working properly. The computer sees the drives and mounts it but in Disk Utility it says it needs to rebuild the Raid. It trys but in the end it fails. When I connect these back to my G4 with 10.5 they work fine. Is this a problem moving a Raid 1 drive form one computer to another or is it a Western Digital problem and I need to take it up with them?