I believe there are 3 ways to activate the k screen lock:
- drop down menu from "log out"
- ctrl-alt-L (default setting), and
- drop-down menu obtained by right-clicking on desktop.

For me, only the third of these works. I'd like to use the keyboard shortcut, but it doesn't work - I tried changing it to something else (in system settings), but it still didn't work.

Any suggestions for fixing this? And why would only one work - don't the three commands do the same thing?

Thanks
James

my setup: kubuntu 13.10; KDE 4.11.5; cairo-dock 3.3.2

You probably have an outdated shortcut entry to the "kscreenlocker" compnent, try assigning the shortcut in the "The KDE Session Manager" component.
About the popup, i don't know, but assume it fires directly and at that time, the popup holds an input grab (what will make the locker fail as it cannot obtain that grab)

Thanks for your answer. How do I access "The KDE Session Manager" component?
I only know the System Settings thing, with its "Shortcuts and Gestures" component.

Replying to myself (in case anyone else is interested) - I found "The KDE Session Manager" and luebking's suggestion works:

In System Settings, choose "Shortcuts and Gestures" and then Global Keyboard Shortcuts. Now the important thing that I missed before was to choose "The KDE Session Manager" rather than "kscreenlocker" from the drop-down menu labelled "KDE Component:" (you'll need to scroll down).
Then enter a shortcut for "Lock Session".

Hope that helps someone else.

Thanks leubking.