A little over a week ago I picked up an 1.6GHz PowerMac G5 along with a 22" ACD screen. The system works fine and I am looking to sell it for what I paid for it (I'm starting to get too many PowerMacs). For my own reasons I wanted to keep the 80GB hard disk for my 1.8GHz system so I pulled the SSD out of the 1.8GHz system and installed it in the 1.6GHz. The 1.6GHz system booted from the OS (Leopard) which was already installed on the SSD. As someone who does not like to sell Macs with personal information I pulled the SSD, connected it to my PC, and used the manufacturers utility to erase the SSD. I then reinstalled it into the 1.6GHz and proceeded to install a fresh copy of Leopard. Upon returning to the system I found it had boot from the Leopard DVD and was back at the start of the install. Thinking I did something wrong I reinstalled the OS. Again the system restarted from the install media. I tried a number of things to troubleshoot this and the only thing I can think of is the SSD is not compatible with this system. I pulled the SSD and installed it in my 2.7GHz system and it booted to the initial configuration after an OS install (meaning the OS had actually installed on the SSD from the 1.6GHz system). Thinking maybe there was a problem with the SATA controller on the 1.6GHz system I installed the hard disk (non SSD) from the 2.7GHz system. To which the system booted right to the desktop. It's weird in the 1.6GHz system booted from the SSD the one time and, after being erased, has failed to boot in the 1.6GHz since. It boots fine in the 2.7GHz system and the 2.7GHz systems HD boots fine in the 1.6GHz system. The installer, both Tiger and Leopard, see the SSD when it is installed in the 1.6GHz system. The Disk Utility from the install media, both Tiger and Leopard, sees and can work with the SSD. It just can't boot from the SSD. I've attempted to reset the PRAM and also attempted to see it as a bootable device when holding down the Option key...it does not show as a device. My conclusion is it's not compatible with the older system but I'm puzzled as to how it booted that one time prior to being erased. Does anyone have any thoughts?