Error al modificar Unity con Ubuntu Tweak (este módulo encontro un error al cargarse)

[Jorge Alexander]

Distribution: Ubuntu 11.10 oneiric
Application: Ubuntu Tweak 0.7.0-0~bzr1740+20120327~oneiric1
Desktop:ubuntu

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/main.py", line 434, in _load_module
    page = module()
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/tweaks/unity.py", line 153, in __init__
    hbox.pack_start(self.create_edge_setting(), True, False, 0)
  File "/usr/lib/python2.7/dist-packages/ubuntutweak/tweaks/unity.py", line 296, in create_edge_setting
    pixbuf = icon.get_from_name('ubuntu-tweak', size=128)
NameError: global name 'icon' is not defined