gtk-sunlight doesn't work on xfce

Hi,
I'm running Xubuntu 12.04 and i just install gtk-sunlight.

It doesn't work.
I mean, it run:

gtk-sunlight
killall: killall.c :386 : kill_all: L'assertion « process_age_sec > 0 » a échoué.
Aborted (core dumped)
Aucune valeur définie pour « /desktop/gnome/background/primary_color »
Aucune valeur définie pour « /desktop/gnome/background/secondary_color »
sunlight_options created
  % Total % Received % Xferd Average Speed Time Time Time Current
                                 Dload Upload Total Spent Left Speed
100 138k 100 138k 0 0 124k 0 0:00:01 0:00:01 --:--:-- 149k

but it doesn't change the wallpaper.

I read here (https://bbs.archlinux.org/viewtopic.php?id=118142) that it's because gtk-sunlight call gnome envirenoment to change wallpaper.

So maybe there is a way to detect desktop environment and adapt...

Caus it's too bad this great soft only work on gnome.

Thanks for considering.