The default profile for ppc32 in ${PORTDIR}/profiles/default-linux/ppc/ppc32/make.defaults does not include 'radeon' in the VIDEO_CARDS section, but includes an inexistent 'ati' driver. This causes the default profile not to build the 'radeon' driver by default, and requires a re-build of the packages 'mesa' and 'xorg-server', with proper VIDEO_CARDS, for the display manager to be brought up. (PPC32 machines with 'radeon' cards are common enough.) (This beats the purpose of the G4 packagecd, on G4 machines with 'radeon' cards.) Reproducible: Always
It was unfortunately missed for the release, but there's not much we can do about it right now, sorry. Originally the flag was just ati, nobody changed it after the ati package was split. It's already been fixed in the non-networked tree and it will be fixed in 2007.1. Thanks for bringing it to our attention though! We'll need to add this to our errata for this release, I'll leave this bug open until we do.
I've added a note in the FAQ. Sorry again about the trouble.