Multiprocessing error in QGIS with Python on Windows?

I have this error when I try to use Manager() from python multiprocessing library. (Just start QGIS open Python console and execute the two following lines)

>>> import multiprocessing
>>> mgr = multiprocessing.Manager()
Traceback (most recent call last):

  File "", line 1, in 
  File "C:\DEV\osgeo4w_dev\apps\Python27\lib\multiprocessing\__init__.py", line 99, in Manager
    m.start()
  File "C:\DEV\osgeo4w_dev\apps\Python27\lib\multiprocessing\managers.py", line 524, in start
    self._process.start()
  File "C:\DEV\osgeo4w_dev\apps\Python27\lib\multiprocessing\process.py", line 130, in start
    self._popen = Popen(self)
  File "C:\DEV\osgeo4w_dev\apps\Python27\lib\multiprocessing\forking.py", line 252, in __init__
    cmd = get_command_line() + [rhandle]
  File "C:\DEV\osgeo4w_dev\apps\Python27\lib\multiprocessing\forking.py", line 339, in get_command_line

    if process.current_process()._identity==() and is_forking(sys.argv):
AttributeError: 'module' object has no attribute 'argv'
>>> 

It happens in both 1.8 and 1.9 dev version on Windows. Of course everything is ok using QGIS on Linux!... :P

It seems something related to the main Python/QGis process startup and the way the library tries to start a new process.... but I can't figure out any workaround.

Any idea? (already posted this on qgis dev list but had no response...)