I have a Powerbook G4 15" and I'm trying to install Leopard onto another external HD of mine. So I use Disk Utility, make a partition (I don't have to option for HFS, so I choose Mac OS Extended (Journaled) and it creates the partition no problem. I open up the DVD package, find the installer follow the steps but when I get up to choosing which volume to install Leo too it won't allow me to select my newly formatted drive and gives me this error "You cannot install mac os x on this volume. mac osx cannot start up from this volume". I have tried iPartition and HFS option, and used a Boot OSX partition option but still the same problem. Does anyone have any suggestions?