Brain Transplant

For some reason, I've been unable to get two successful Mac brain transplants to boot without fussing. I just received a new Power Mac dual 1.25 GHz system -- my first upgrade in 2 1/2 years. Instead of cloning or otherwise duplicating files from my Cube, I simply inserted the Cube's drive into the empty drive bay. No matter what I did, however, I could not get the Cube's OS X 10.2.4 system to boot. (I checked the jumpers and the master/slave ATA cable and tried different configurations, including making sure both were set to cable select.) The Power Mac recognized the system, and showed it as an option in Startup Disk.Okay, fair enough, I decided to just copy Applications and User settings over, and with about 40 minutes of copying and a little configuration, I had the new machine set up to work like the old. So no biggee, but not very Mac like. The second brain transplant took an empty new drive now in my Cube, and a cloning operation from my home iMac. I ran Carbon Copy Cloner after mounting the Cube in FireWire disk mode. I used Disk Utility to initialize the drive, and then CCC to copy all the files. I shut down, removed the FireWire cable, and booted the Cube. It wouldn't boot! I ran Disk Utility from the Jaguar boot disk, and there were no significant permission errors and no disk catalog problems. Reboot, reboot, reboot, checked jumper settings, no luck. I ran the Jaguar installer, archiving the installation that was in place (as it was 10.2.4 and I only have 10.2.3 disks), and then downloading about 150 Mb of OS X updaters, since I didn't have those stored at home. The system is fine now, and, once again, pretty much like the iMac's was. I can't figure out the common factors in both cases. Perhaps I need Disk Warrior to make sure I can create or migrate bootable disks? I've never had these difficulties with even older versions of OS X or ever with OS 9. (Do you have to bless System folders in OS X?)