I have an old g4/400 (agp) that I upgraded to a 1600mhz machine with a processor card. I was running 10.4.8 at the time. Have a gig of ram. Went to upgrade to 10.5 and it kept failing...crashing I guess. I can get to the installer but it would fail. So, I read that there was a problem with the Apple Partition setup so I booted up Disk Utility and went with the GUID partition. The Leopard installer came up just fine but asked me to repartition back to the Apple Partition. Ok. And now, the installer keeps failing AND because I repartitioned I have no operating system. So, because I've purchased upgrades for 10.4. and 10.5 and since I can't get the 10.3 installation disk installer to work...I'm left with nothing now as the both the 10.4 and 10.5 installer upgrades need 10.3. Completely stuck...any ideas? It's an old machine...I'm not spending another dime upgrading anything...but it's really not fair that this is happening...I've paid for all of this stuff.