Twisted traceback:
Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/twisted/protocols/basic.py", line 240, in dataReceived
    return self.rawDataReceived(data)
  File "/usr/lib/python2.5/site-packages/twisted/web/http.py", line 1051, in rawDataReceived
    self.allContentReceived()
  File "/usr/lib/python2.5/site-packages/twisted/web/http.py", line 1042, in allContentReceived
    req.requestReceived(command, path, version)
  File "/usr/lib/python2.5/site-packages/twisted/web/http.py", line 598, in requestReceived
    self.process()
--- <exception caught here> ---
  File "/usr/lib/python2.5/site-packages/twisted/web/server.py", line 160, in process
    self.render(resrc)
  File "/usr/lib/python2.5/site-packages/twisted/web/server.py", line 167, in render
    body = resrc.render(self)
  File "/usr/lib/python2.5/site-packages/twisted/web/resource.py", line 189, in render
    return m(request)
  File "/home/phil/devel/coherence/coherence/upnp/core/event.py", line 52, in render_NOTIFY
    self.control_point.propagate(event)
  File "/home/phil/devel/coherence/coherence/upnp/devices/control_point.py", line 95, in propagate
    target_service.get_state_variable(var_name, 0).update(var_value)
exceptions.AttributeError: 'NoneType' object has no attribute 'update'