Thanks, Michael. that was one of my suspicions, too. I have an external enclosure with an Oxford 924 chip set on order, and it is my intention to re-clone the drive once it arrives. The vendor is cooldrives.com, and apparently they build to order and do not ship instantly. So, I will have to wait. --Steve At 11:04 PM -0600 1/25/07, Michael Murphy wrote: >I put a 750 GB hd into my original iMac G5 without problem. I did use a Firewire external enclosure for cloning the drive though. This might be your problem. > >Michael