AttributeError: 'NoneType' object has no attribute 'set_text'
Controlador: propiedad 'message_index' cambiada
Traceback (most recent call last):
  File "/mnt/sda6/dirakx/OrfeoStick/control.py", line 31, in on_button1_clicked
    self.model.set_next_message()
  File "/mnt/sda6/dirakx/OrfeoStick/modelo.py", line 30, in set_next_message
    self.message_index = (self.message_index + 1) % len(self.messages)
  File "<string>", line 6, in set_prop_message_index
  File "/var/lib/python-support/python2.5/gtkmvc/model.py", line 261, in notify_property_value_change
    self, old, new) # notifies the change
  File "/var/lib/python-support/python2.5/gtkmvc/model.py", line 249, in __notify_observer__
    return method(*args, **kwargs)
  File "/mnt/sda6/dirakx/OrfeoStick/control.py", line 41, in property_message_index_value_change
    self.view['label_text'].set_text(msg)
AttributeError: 'NoneType' object has no attribute 'set_text'