Messed-up Xubuntu login background at startup

[Laurent Humblet]

Hi,

I have this problem with the Xubuntu login screen :

Before:
http://i.imgur.com/reVrfsc.jpg

Then I do:
CTRL+ALT+F1 + log in
sudo service lightdm restart (sometimes I need to do it twice or three times)

And then after restarting the service:
http://i.imgur.com/clhwntP.png

I've tried multiple manipulations like disabling the dynamic login
background (Gnome settings?) or specify other backgrounds but it
doesn't seem to have
any effect.

I don't get why I have to restart the service sometimes multiple times
to get the greeter background to display properly.

Thank you for your time and help,
Laurent