Bug#538694:

[ottoshmidt]

I solved that bug: the thing is that on debian testing fresh install the
version of it is:
Package: gnome-screensaver
Version: 2.26.1-1 while gnome-session package and gnome-settings-daemons ar of
older versions.

Fix:

Install gnome-sessions and gnome-settings-daemon the same version as gnome-screensaver
I did it from Sid packages and istalled 2.26.. versions of those three..

After reboot all works fine...

Oto