I just bought a MacPro and I'm trying to use the OS X install disc to load Leopard on my PowerBook G4 (1.25GHz, 1GBRAM), but it's not working. It goes through the process until the startup screen, then says I can't load it on this computer. It doesn't say why, though. Is there anything I can do to get this to work? Is the disc that comes with the Mac Pro different than the disc that comes with Leopard in the box?