Hi, I have an old PowerMac G4 that I am trying to update for my girlfriend's use. It is currently running the ancient 10.2.8 and I am trying to update to 10.4 for her. While running the install DVD it will begin to install and then quit abruptly saying "Error while upgrading. Please try again." Does anyone know why this might be happening? Any suggestions? I thought maybe the disc was a little dirty but I cleaned it off and it's still happening. Also, it is definitely a retail version of Tiger, not a system-specific edition. Thanks!