by CiaW on Sun Dec 19, 2010 8:40 pm
Was it just the update that locked up? If so, you may want to just kill that process or application (or maybe log out of the desktop) rather than doing a hard-reboot, in future.
To fix it, you said you can't start up anything, so what you could try is to shell out to a terminal (ctrl-alt-f4) or any fn key from 1 to 6 I think and then log in at the prompt, and then type sudo apt-get update && sudo apt-get upgrade. That will actually pull in even the level 4 and 5 updates.
If you've installed debdelta, you can use: sudo debdelta-upgrade after the apt-get update, instead. Then reboot, you can use 'sudo shutdown -r now' (no quotes) and hopefully you'll be back to a normal login window and desktop...