dconf default configuration with Keyfile Directories not working

[R.Ladinig]

Ubuntu Trusty Tahr 14.04 , Updates;

dconf-cli:
  Installiert: 0.20.0-1

root@O2-10-PCT2:~# apt-cache policy dconf-gsettings-backend
dconf-gsettings-backend:
  Installiert: 0.20.0-1

root@O2-10-PCT2:~# apt-cache policy gsettings-desktop-schemas
gsettings-desktop-schemas:
  Installiert: 3.10.1-0ubuntu1

I tried to set default values for 'org/gnome/desktop/interface' with:

Profile:
root@O2-10-PCT2:~# cat /etc/dconf/profile/user
user-db:user
system-db:local
system-db:site

Keyfile Directory:
root@O2-10-PCT2:~# cat /etc/dconf/db/site.d/10_site__theme
# dconf path
[org/gnome/desktop/wm/preferences]
# dconf key names and their corresponding values
org.gnome.desktop.wm.preferences theme='Ambiance'

# dconf path
[org/gnome/desktop/interface]
# dconf key names and their corresponding values
org.gnome.desktop.interface cursor-theme='DMZ-White'
org.gnome.desktop.interface icon-theme='ubuntu-gnome-dark'
org.gnome.desktop.interface gtk-theme=string "Ambiance"

dconf update

I deleted the users dconf-file:
rm ~/.config/dconf/user

user log out -> log in -> the default setting didn't work for me.

* different output for gsettings and dconf:

root@O2-10-PCT2:~# gsettings get org.gnome.desktop.interface gtk-theme
'Adwaita'

root@O2-10-PCT2:~# dconf dump /org/gnome/desktop/interface/
[/]
org.gnome.desktop.interface icon-theme='ubuntu-gnome-dark'
org.gnome.desktop.interface gtk-theme='Ambiance'
org.gnome.desktop.interface cursor-theme='DMZ-White'

-> strace gsettings get org.gnome.desktop.interface gtk-theme

shows that /etc/dconf/db/site and /etc/dconf/local are opened by gsettings;

BUT:
The value in /etc/dconf/site is 'Ambiance'
the Output is 'Adwaita'

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.