What causes nodeValue to be None?
Im trying to connect to facebook, my lack xml experiance with python is letting me down. Can anyone explain the following?

Code:
def getReply(self, params):
  req = urllib.urlopen(facebook.getURL(params))
  tokenXML = req.read()
  req.close()
  print 'Raw data: ', tokenXML
  return tokenXML

tokenXML = parseString(facebook.getReply(params))
token
...