Comment 3 for bug 1055874

@Sparhawk
and if your sleep-inactive-(ac|battery)-type is suspend

the actual suspend time will be

sleep-inactive-(ac|battery)-timeout + idle-dim-time

but if your sleep-display-(ac|battery) > sleep-inactive-(ac|battery)-timeout

the actual suspend time will be

sleep-display-(ac|battery) + idle-dim-time

hope these explains the default behavior in ubuntu now.

btw, this should related to gnome-setttings-daemon not gnome-power-manager , and it's indeed has some design issue,

there is a upstream fix already submitted. ( https://bugzilla.gnome.org/show_bug.cgi?id=668703 )

but not yet in precise (and quantel), I'd assume this is going to be changed in 13.04.