Impossible to load module "impostazioni d'accesso"

[eboumis]

Distribution: Ubuntu 10.10 maverick
Application: Ubuntu Tweak 0.5.9
Desktop: gnome

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/mainwindow.py", line 433, in setup_notebook
    page = module()
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/modules/loginsettings.py", line 74, in __init__
    self.__setup_logo_image()
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/modules/loginsettings.py", line 110, in __setup_logo_image
    pixbuf = gtk.gdk.pixbuf_new_from_file(path)
GError: Apertura del file «/tmp/tmpbN2ApX» non riuscita: Permesso negato

[marcoubuntu84 (markoubuntu84)]

Distribution: Ubuntu 12.04 precise
Application: Ubuntu Tweak 0.7.0-1~precise4
Desktop:gnome-classic

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/loginsettings.py", line 82, in __init__
    self._setup_logo_image()
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/tweaks/loginsettings.py", line 95, in _setup_logo_image
    self.logo_image.set_from_file(logo_path)
  File "/usr/lib/python2.7/dist-packages/gi/types.py", line 43, in function
    return info.invoke(*args, **kwargs)
TypeError: Must be string, not NoneType