since upgrading to dbus-1.2.12, my logs are filled with: Apr 30 00:54:19 keitaro dbus-daemon: Rejected send message, 2 matched rules; type="method_call", sender=":1.27" (uid=1000 pid=6228 comm="gnome-session ") interface="org.freedesktop.ConsoleKit.Session" member="SetIdleHint" error name="(unset)" requested_reply=0 destination="org.freedesktop.ConsoleKit" (uid=0 pid=5835 comm="/usr/sbin/console-kit-daemon ")) on gnome-2.26 and similar message but from gnome-screensaver on gnome-2.24
This was fixed in consolekit-0.3.0-r1.