Traceback (most recent call last):
  File "/usr/share/system-config-printer/newprinter.py", line 3089, in on_tvNPMakes_cursor_changed
    self.fillModelList()
  File "/usr/share/system-config-printer/newprinter.py", line 3093, in fillModelList
    models = self.ppds.getModels(self.NPMake)
AttributeError: 'NoneType' object has no attribute 'getModels'