Comment 9 for bug 673775

The root of this issue seems to be this python bug in xmlrpclib: http://bugs.python.org/issue1223

It was fixed in Python 2.6, but not in earlier version, so the problem should be reproducible on all Python 2.5 versions, not just Windows. Of course, since Python 2.5 is currently packaged with the OpenERP Windows installer, Windows clients are likely to have this problem.
If you have a working OpenERP Server with XML-RPCS enabled, you can do the following test to see if you can reproduce the error:

On Python 2.4 or 2.5 it fails:

Python 2.5.5 (r255:77872, Sep 14 2010, 17:19:13)
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import xmlrpclib
>>> s = xmlrpclib.ServerProxy('https://localhost:8071/xmlrpc/common')
>>> uid = s.login('some_db','admin','admin')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.5/xmlrpclib.py", line 1147, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python2.5/xmlrpclib.py", line 1437, in __request
    verbose=self.__verbose
  File "/usr/lib/python2.5/xmlrpclib.py", line 1201, in request
    return self._parse_response(h.getfile(), sock)
  File "/usr/lib/python2.5/xmlrpclib.py", line 1328, in _parse_response
    response = sock.recv(1024)
  File "/usr/lib/python2.5/httplib.py", line 1113, in recv
    return self._ssl.read(len)
socket.sslerror: (8, 'EOF occurred in violation of protocol')

On Python 2.6 it just works:

Python 2.6.6 (r266:84292, Sep 15 2010, 16:22:56)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import xmlrpclib
>>> s = xmlrpclib.ServerProxy('https://localhost:8071/xmlrpc/common')
>>> uid = s.login('test_install2','admin','admin')
>>>