Was reading that blogpost : http://www.mattfischer.com/blog/?p=431 and then checked my system.
What i've seen:
- the dconf-tool settings , for example : the chosen background, are not writen inside the user profile.
- worst, dconf use the wired default setting, as my "user" is not created by the configuration process.

So i wonder about how is your config settings about dconf : mainly /.config/dconf/ & /etc/dconf/profile/.
As profile, i only have "gdm", but not my login username.
But my system is an PP dist-upgrade, not a fresh install, so maybe a difference exist.