Boot args for booting Fedora 12 ppc DVD

Hi, I had posted earler that just pressing enter at the boot prompt all I get is a white screen. Then Alex Kanavin said to try video=ofonly Which I have not tried, sorry to say - because in the same message Alex suggested I try the ubuntu ppc, which I downloaded and burned on my F13 (x86) machine. I booted it on the powerbook G4 in 32 bit mode and I chose the live-powerpc and it came up just fine. For the record, I tried the args video=ofonly live-powerpc64

and it failed to boot (memory fault).

So, is the Powebook G4 a 32 only bit powerpc cpu or is the dvd I downloaded for the 32 bit only? If the DVD is for 32 bit only, then when I press the tab key for the boot args, why would it print the option to boot in 64 bit mode?