I am running Fedora 17 with GNOME 3 as my desktop, and have set up the machine to hibernate after idle for 1 hour. However, instead of switching off the machine appears to be on with the fan running.
When I run pm-hibernate from the command line, I get the expected hibernate behavior.
Also, KDE4 desktop hibernates correctly after the timeout occurs.
So I believe that the mechanism GNOME 3 is using to initiate hibernate is problematic. Where can I manually inspect what GNOME 3 is executing to accomplish the hibernate? And how can I modify it to run pm-hibernate as I do successfully from the command line?
I am adding Ubuntu 12.04 tag to this in addition to fedora-17, because I believe I saw the same behavior back when I had that OS installed.