Comment 12 for bug 227844

Stopping GDM before shutting down doesn't work either.

The power-off problem was relatively rare until I applied the following updates [commit log - attached].
After these updates the problem became VERY frequent. (re-installing initscript seemed to help for a while).

I don't know if anything can be teased from the information or if it's just more noise.
Hopefully the former, apologies if the latter.