The 10.3 disk utility may not recognize the GUID format of the external HD. Can you upgrade to System 10.4? You may have the same problem with the 10.3 not seeing the newer internal optical drive. Try hooking it up in target mode via a firewire cable to another mac. Boot holding the "T" key down to both upgrade to 10.4, run the disk utility and also see if the optical drive is seen by the 10.5 system. This machine will run on 10.5 if you have enough RAM all may be a bit slow.
The 10.3 disk utility may not recognize the GUID format of the external HD. Can you upgrade to System 10.4? You may have the same problem with the 10.3 not seeing the newer internal optical drive. Try hooking it up in target mode via a firewire cable to another mac. Boot holding the "T" key down to both upgrade to 10.4, run the disk utility and also see if the optical drive is seen by the 10.5 system. This machine will run on 10.5 if you have enough RAM all may be a bit slow.
The 10.3 disk utility may not recognize the GUID format of the external HD. Can you upgrade to System 10.4? You may have the same problem with the 10.3 not seeing the newer internal optical drive. Try hooking it up in target mode via a firewire cable to another mac. Boot holding the "T" key down to both upgrade to 10.4, run the disk utility and also see if the optical drive is seen by the 10.5 system. This machine will run on 10.5 if you have enough RAM all may be a bit slow.