Hi there, and thank you for any help ahead of time. I just got a used dual 2.0 power mac, model 7,3. It is running Leopard 10.5.8, which was just installed before purchase. Everything seems fine with it until I try to install a dmg file into my applications folder. The computer then freezes and I get a bunch of code gibberish on my screen. Any ideas? I really want to be able to use Firefox and micro torrent on mac.