Cannot set static background in 13.10

[David]

Steps to reproduce:

 * Open dconf editor
 * Set background to '/usr/share/backgrounds/somebackground.jpg' (file is root:root)
 * Set draw-user-backgrounds to false (unticked)
 * Close
 * Set desktop (user) background to inaccessible.jpg (file that cannot be read by lightdm)
 * Restart machine

What should happen:

Greeter loads. Greeter background is somebackground.jpg - does not change if different user is selected, does not change if user background is changed.

What happens instead:

Greeter loads. Greeter background is warty-final-ubuntu.png (default).

Notes:

Could be related to these reports attempting the same from the command line? http://askubuntu.com/questions/379965/lightdm-unity-greeter-wallpaper-will-not-set and http://askubuntu.com/questions/381479/how-to-change-login-screen-background-on-13-10

[David (lofidevops)]

Error message from the linked command line reports (no error reported by dconf editor GUI - settings persist on restart):

    (process:6517): dconf-CRITICAL **: unable to create directory '/run/user/1000/dconf': Permission denied. dconf will not work properly.

[David (lofidevops)]

I am now using 14.04 not 13.10 and no longer using a static background, but am happy to adjust settings to test.