Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/displayconfiggtk/DisplayConfig.py", line 301, in on_radiobutton_gfxcard_model_toggled
    self.on_treeview_gfxcards_cursor_changed(self.treeview_gfxcards)
  File "/usr/lib/python2.5/site-packages/displayconfiggtk/DisplayConfig.py", line 270, in on_treeview_gfxcards_cursor_changed
    card = model[cursor_path][1]
TypeError: 'NoneType' object is unsubscriptable