OpenSUSE on a G4

I am trying to install OpenSUSE 10.2 PPC on to my old Power Mac G4, but I cannot get it to boot from the disc drive. I have tried holding C and even tried Cmd+Option+Del+Shft after a reboot but it continues to load OSX.

Am I missing something simple here?

Appreciate any help!

[EDIT] BTW, this is not a dual-boot....only linux on this one.