Comment 16 for bug 410829

I started seeing this bug in Ubuntu Natty, and I don't know if the cause was the same but I'm adding my experience here for others that find it via googling. In my case, it turned out that since the upgrade, my "suspend" button was now being interpreted as a "hibernate" button instead. There was no entry in gconf for a hibernate command, so it didn't know what to do.

The error in gnome-power-manager was:

- action: /apps/gnome-power-manager/buttons/hibernate set to blank (The hibernate button has been pressed.)

Adding a key called /apps/gnome-power-manager/buttons/hibernate and setting that to the value of "suspend" fixed the problem