$ python test.py
Traceback (most recent call last):
  File "test.py", line 27, in <module>
    adapter.DiscoverDevices()
  File "/var/lib/python-support/python2.5/dbus/proxies.py", line 85, in __call__
    return self._proxy_method(*args, **keywords)
  File "/var/lib/python-support/python2.5/dbus/proxies.py", line 169, in __call__
    reply_message = self._connection.send_message_with_reply_and_block(message, timeout)
dbus.DBusException: org.bluez.Error.Failed: Invalid argument