Cant change desktop setting back to default

[<JD v Tongeren mindef nl>]

Dear Sir/Madam,
I am having a problem with GCONF.  I want to restore it to default settings, so I can change the image location of the image. As it was placed on the desktop which I do not find an appropriate place for desktop backgrounds. 
I wanted to make it so that people can't change there desktop backgrounds so I used the gconf. Looked up to the settings from modules gnome--> background. And then I set all the options as "Set as mandatory". Now the problem is. I moved the image to a different location, I changed the background path  location in the gconf editor (picture_filenname) now when I quit. It won't change. As soon as I open GCONf it will show me same settings as I put in first. Meaning all the keys are not writable.  And the background path is still the same as the first time as I put it in.
My config info
I am running Fedora 3
Output of ps jaxwww | grep gconf
    1  2918  2847  2847 ?           -1 S        0   0:07 /usr/libexec/gconfd-2 5
 3052  3086  3085  3052 pts/2     3085 S+       0   0:00 grep gconf
Thanks in advance

Jean-Paul