Comment 2 for bug 231397

I've discovered that this behaviour is deliberate and gnome-power-manager (gpm) relies on gnome-screensaver (gss) to implement the blanking and DPMS instead of X. It behaves correctly when gnome-screensaver is running.

It would have been nice to be able to use gpm without gss, because for most people there's no point in a screensaver that does anything except save power. However, gss does provide a way of suspending blanking for video players etc:- gnome-screensaver-command --poke - which is better than temporarily changing the X settings, so it's got its uses after all.

Although I think it might be preferable for gpm to handle DPMS for gss instead of the other way round, I don't mind if this bug is closed without anything being changed.