I was looking for an easy way to do this, but apparently gnome's pwr mgmt options dont let you shut the system down after it becomes idle. Here's one work around, let me know if you have a better way


Create a new script to make stuff work
Code:
sudo touch /etc/pm/sleep.d/10_shutdown
become root, then fill it with goodies :
Code:
#!/bin/bash

. /usr/lib/pm-utils/functions

case "$1" in
    hibernate|suspend)
    shutdown -h now
    ;;
    *)
    ;;
esac
Set it to be executable
Code:
sudo chmod +x /etc/pm/sleep.d/10_shutdown