linuxbridge_quantum_agent TypeError: wait() got an unexpected keyword argument 'timeout'

I'm trying to run linuxbridge_quantum_agent on RHEL6.3.
When running I get this error:

# ./linuxbridge_quantum_agent.py --config-file /etc/quantum/plugins/linuxbridge/linuxbridge_conf.ini
Traceback (most recent call last):
  File "./linuxbridge_quantum_agent.py", line 827, in <module>
    main()
  File "./linuxbridge_quantum_agent.py", line 814, in main
    root_helper)
  File "./linuxbridge_quantum_agent.py", line 629, in __init__
    self.setup_rpc(interface_mappings.values())
  File "./linuxbridge_quantum_agent.py", line 635, in setup_rpc
    devices = ip_lib.IPWrapper(self.root_helper).get_devices(True)
  File "/usr/lib/python2.6/site-packages/quantum-2012.2.1-py2.6.egg/quantum/agent/linux/ip_lib.py", line 71, in get_devices
    self.root_helper, self.namespace)
  File "/usr/lib/python2.6/site-packages/quantum-2012.2.1-py2.6.egg/quantum/agent/linux/ip_lib.py", line 56, in _execute
    root_helper=root_helper)
  File "/usr/lib/python2.6/site-packages/quantum-2012.2.1-py2.6.egg/quantum/agent/linux/utils.py", line 49, in execute
    obj.communicate())
  File "/usr/lib64/python2.6/subprocess.py", line 729, in communicate
    stdout, stderr = self._communicate(input, endtime)
  File "/usr/lib64/python2.6/subprocess.py", line 1330, in _communicate
    self.wait(timeout=self._remaining_time(endtime))
TypeError: wait() got an unexpected keyword argument 'timeout'

I used the git repository branch stable/folsom.

Please advise,
Itzik