Hi - I'm writing on behalf of a friend. He's got a 15" PowerBook, the most recent one, and it was running Tiger. He's inserted a genuine Leopard DVD and installed it. The installation goes fine until he boots his laptop up after installation. The computer loads up the desktop, dock and most of the items in the grey bar at the top (like clock etc), but the desktop is empty, and there is the eternal spinning beach-ball. He's now reinstalled twice, and it still does the same thing. Any suggestions?