Lock Screen doesn't work

[Guest]

I'm running Kubuntu on my netbook (with the netbook UI), but none of the lock screen functions (including the panel button and automatic locking from the power manager) work. They simply do nothing.

I have installed a bunch of screensaver-related packages to try to solve the issue, but this has not worked. The command "xdg-screensaver activate" does work, but "qbus org.freedesktop.ScreenSaver /ScreenSaver Lock" does not, resulting in "Service 'org.freedesktop.ScreenSaver' does not exist."

My guess is that there's something missing from my installation/configuration, but I have no idea what. Anyone have any ideas?

[Guest]

Further investigation shows that if I run "xdg-screensaver" from menu's "run command" option, the lock/screensaver functionality works thereafter for the rest of the session.

However, despite adding "xdg-screensaver" to the startup applications list, I can't seem to get this to happen automatically. Some help would be appreciated...