Comment 15 for bug 366222

Thank you for taking the time to report this bug and helping to make Ubuntu better.
Unfortunately, we can't fix it because your description didn't include enough information.

Next time this happens, can you switch to a text console by hitting
CTRL + ALT + F1, login there, and then run
sudo apport-collect -l linux 366222
then run
sudo poweroff and see if the machine powers off

If the machine still won't shutdown then run
'top' and it might tell you what the machine is stuck on

If you know how you can probably kill the X server and relogin w/o
shutting down the machine
thanks
~