I've got the strangest problem, it's probably something simple: The system boots, shows the apple and volume, brightness controls and mouse pointer, but nothing else. Not a menu, no finder, nada, Reboots bring me back to the same point, can't bring up a repair console, I inserted an OSX DVD, which I can hear running but it still doesn't show anything on the screen. It's not dark, it just looks like the desktop has been wiped clean. I can move the mouse and get sounds from it (using the vol button) but I get nowhere. Any ideas?