cannot disable compiz

[scar <scar@drigon.com>]

i wanted to try out compiz after updating to squeeze, but unfortunately
it's not too stable on my old system and the WM crashes regularly.  so,
i'd like to revert back to the default WM.

i followed http://wiki.debian.org/Compiz to try compiz and now i should
be able to revert back by using this command:

gconftool-2 --type string --set
/desktop/gnome/session/required_components/windowmanager gnome-wm

for some reason though, when i reboot and log back in compiz is still
loading.  i've checked the gconf setting and it is indeed set to
gnome-wm so i'm not sure what's going on.