when I just start the cobbler daemon I get this error message

# service cobbler start
Starting cobbler daemon: Traceback (most recent call last):
  File "/usr/bin/cobblerd", line 32, in <module>
    api = bootapi.BootAPI()
  File "/usr/lib/python2.5/site-packages/cobbler/api.py", line 70, in __init__
    self.deserialize()
  File "/usr/lib/python2.5/site-packages/cobbler/api.py", line 364, in deserialize
    return self._config.deserialize()
  File "/usr/lib/python2.5/site-packages/cobbler/config.py", line 169, in deserialize
    if not serializer.deserialize(x,topological=True):
  File "/usr/lib/python2.5/site-packages/cobbler/serializer.py", line 92, in deserialize
    rc = storage_module.deserialize(obj,topological)
  File "/usr/lib/python2.5/site-packages/cobbler/modules/serializer_yaml.py", line 100, in deserialize
    datastruct = yaml.load(data).next()  # first record
  File "/usr/lib/python2.5/site-packages/cobbler/yaml/load.py", line 83, in next
    self.nestedDocs.nestToNextLine()
  File "/usr/lib/python2.5/site-packages/cobbler/yaml/stream.py", line 131, in nestToNextLine
    indentation = indentLevel(line)
  File "/usr/lib/python2.5/site-packages/cobbler/yaml/stream.py", line 6, in indentLevel
    while n < len(line) and line[n] == ' ':
TypeError: object of type 'NoneType' has no len()

CAN any one help me to overcome this problem