I have a Powerbook G4 (circa 2005/6) that I'm trying to install Linux on to. It absolutely refuses to boot from a CD! Linux installation CD, Mac OS X installation CD, etc. Here are the methods I have tried: Holding C during boot: unsuccessful Holding Cmd+Option+Shift+Del during boot: unsuccessful Holding Option during boot: Disc shows up in boot menu, but when I click on it, the screen flickers and returns to the boot menu In Mac OS X, using the Startup Disk control panel: this works for the Mac OS X install discs, but my Linux install discs do not show up to be selected for this. I should also note that the disc shows up in Finder and mounts no problem, and my even older iBook boots from the disc just fine (holding the C key) Also I am indeed using a PPC distro disc (Ubuntu PPC Live CD). What else do you think I can try? This has been frustrating me for the past two days.