I've notice this error in master.log. They are always the same but do not seem to cause and issue nor can I see what they related to.

[rosmaster.master][INFO] 2013-10-30 12:16:55,711: publisherUpdate[/tf] -> http://viki:58692/
[rosmaster.master][INFO] 2013-10-30 12:16:55,712: publisherUpdate[/rosout] -> http://viki:53534/
[rosmaster.master][INFO] 2013-10-30 12:16:55,712: publisherUpdate[/tf] -> http://viki:40846/
[rosmaster.threadpool][ERROR] 2013-10-30 12:16:55,712: Traceback (most recent call last):
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rosmaster/threadpool.py", line 218, in run
    result = cmd(*args)
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rosmaster/master_api.py", line 189, in publisher_update_task
    xmlrpcapi(api).publisherUpdate('/master', topic, pub_uris)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1224, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1578, in __request
    verbose=self.__verbose
  File "/usr/lib/python2.7/xmlrpclib.py", line 1264, in request
    return self.single_request(host, handler, request_body, verbose)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1297, in single_request
    return self.parse_response(response)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1473, in parse_response
    return u.close()
  File "/usr/lib/python2.7/xmlrpclib.py", line 793, in close
    raise Fault(**self._stack[0])
Fault: <Fault -1: 'publisherUpdate: unknown method name'>