ok, so there i was, surfing away for nothing in particular, a bit bored. for no reason whatsoever i suddenly thought "i know, why don't i change the screen resolution to 800x600". no good reason, just did it. the screen went black - and stayed black. as if the resolution is unsupported (although it's there in the menu). i thought that if i left it it might revert back to 1200x800, but no joy. i rebooted by holding down the power key until it went off then turning it back on. the grey startup screen came up initially, but then the screen just went black again. any ideas how i can fix this? if it helps i've got an external firewire drive that i can boot into, but unfortunately i've not got ssh or vnc enabled. help!!