Comment 25 for bug 436724

Same problem here. Karmic up to date as of now.
Lock Screen from the applet does nothing. Running the command gives:

bob@bob-desktop:~$ dbus-send --print-reply --reply-timeout=100 --dest=org.gnome.ScreenSaver / org.gnome.ScreenSaver.Lock
Error org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.ScreenSaver was not provided by any .service files

Tried changing some settings regarding screensaver and in gconf-editor, but it makes no difference.

Probably doesnt matter, but Im using 2 monitors.