launching desktop icond from within ubuntu tweak

Distribution: Ubuntu 12.04 precise
Application: Ubuntu Tweak 0.7.1-1~precise1
Desktop:default

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/main.py", line 497, in _load_module
    page = module()
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/tweaks/icons.py", line 129, in __init__
    setting_list.append(DesktopIcon(item))
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/tweaks/icons.py", line 62, in __init__
    backend="gsettings")
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/factory.py", line 48, in create
    return getattr(cls, 'do_create')(widget, **kwargs)
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/factory.py", line 93, in do_create
    new_widget = globals().get(widget)(**kwargs)
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/gui/widgets.py", line 49, in __init__
    SettingWidget.__init__(self, key=key, default=default, type=bool, backend=backend)
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/gui/widgets.py", line 25, in __init__
    self._setting = GSetting(key=key, default=default, type=type)
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/settings/gsettings.py", line 26, in __init__
    raise Exception('Oops, Settings schema "%s" is not installed' % self.schema_id)
Exception: Oops, Settings schema "org.gnome.nautilus.desktop" is not installed