FOLLOW-UP: EFI MacBook Pro Firmware Issue SOLVED (for me, at least)

[GGD]

I think the real restriction is that the OSX Installer will not install an Intel OSX on a APM partitioned drive. The Intel Macs will however boot an Intel OSX from an APM drive. I think if you clone an Intel OSX volume from a GUID drive to an APM drive it will boot from that APM drive.

Cloning might have been the way that Zoidberg got into this situation in the first place.