My Ubuntu hanged. I restarted it. But it got stuck at  "Starting Winbind daemon" point. I restarted it again. It stuck there again. I randomly pressed keys, and what got it moving was the classics Ctrl+Alt+Del. It did not restart Ubuntu. On the contrary, it helped Ubuntu pass the "Starting Winbind daemon" point and proceed normally into the login prompt. By the way, I'm using the Jaunty Jackalope.