Wallpaper is not changing and right click does not work on desktop in Ubuntu 14.04

I had the exact same problem.
Tried everything in the book!
This is what worked for me.
Hope your problem is solved soon.

gsettings set org.gnome.settings-daemon.plugins.background active true

After installing or removing of ubuntu-gnome-desktop a bug of Desktop not responding to clicks/icons can occur, You may reactivate:

Active Desktop Background:

gsettings set org.gnome.settings-daemon.plugins.background active true

Active Desktop Icons:

gsettings set org.gnome.desktop.background show-desktop-icons true

Use the gnome-tweak-tool. Click the Desktop button (left side) Set:

Mode = Scaled
Background Location = ...image path