Why is this pirating software when I am allowed to download it from apple? If you have an ADC account, you are a beta tester rather than a software pirate! This is not some dodgy version of Jaguar I downloaded from Hotline... and I do not distribute my downloads to anyone else.
I think the reason it won't install on my B+W is that the XLR8 zif modifies the firmware to allow the G4 to boot. I have had no problems installing on my Ti550, Ti800 or my PBG3 300 lombard. Either that or my CD-Rom is screwed...
Anyway Jaguar is too close to GM now for a bug like that to still exist, so if it is a bug, i don't think it will be fixed in time, nevertheless I have reported the bug to Apple.