Please check your GNOME packages with schemas files
The default schemas location has changed about one month ago
from /etc/gconf/schemas to /usr/share/gconf/schemas.
To handle this change in a proper way you need you should use dh_gconf.
I've noticed that a lot of GNOME packages still have a static postinst
file for this with /etc hardcoded in it. So please use dh_gconf in your
debian/rules (if you use CDBS the gnome.rk rules take care of it) and
remove the schemas registration from the postinst (most of the GNOME
packages only have gconftool-2 and scrollkeeper here, since both are
handled by dh_scrollkeeper/dh_gconf you can remove the script in this
Feel free to contact me if you have a question or need some help. It
would be nice to have most the schemas completly moved to /usr for sarge