Can not re-enable display restart button on the login screen in Gnome after disabling in Red Hat Enterprise Linux 5

Issue

• Cannot enable the restart / shutdown button on the gdm login screen.

• Using gconftool to change /apps/gdm/simple-greeter/disable_restart_buttons to true does not enable the gdm restart buttons.

• Cannot re-enable the gdm restart button after changing the above key back to default in the gconf-editor.