Comment 3 for bug 494366

Yes, without success.

Logged in as root, I ran

#> sudo -u gdm gconftool-2 --type boolean --set /apps/gdm/simple-greeter/disable_restart_buttons 1
#> sudo -u gdm gconftool-2 -g /apps/gdm/simple-greeter/disable_restart_buttons
true

After restarting gdm or rebooting the machine, the GDM greeter still shows the shutdown, suspend, and hibernate options and they still work.