Starting Xfce on live CD

I’m trying to build a live CD with Xfce as the desktop environment through the Suse Studio. I can’t get around installing GDM as the display manager, which chooses to start Gnome as the DE. In /etc/sysconfig/windowmanager I have


Anything else I can do to get Xfce started? I really don’t want Gnome at all on this CD, but the Studio seems to insist it’s necessary.