My G-5 PPC 1.6 GHz is now stuck when booting up after I downloaded the 10.4.11 update from Apple using software update. The OS loading indicator goes all to the right then the OS just sits there. I have waited up to 45 minutes with it stuck in this state twice with no loading of the Dock and main screen. Anyone have any ideas what I should check to get Tiger to finish loading? BTW, I just purchased a Magic mouse and it is the best computer mouse I have ever owned.