I am receiving the same problem.  Log follows: 
 
  File "/opt/odoo/openerp/http.py", line 617, in _handle_exception
    return super(HttpRequest, self)._handle_exception(exception)
  File "/opt/odoo/openerp/addons/base/ir/ir_http.py", line 126, in _dispatch
    result = request.dispatch()
  File "/opt/odoo/openerp/http.py", line 635, in dispatch
    r = self._call_function(**self.params)
  File "/opt/odoo/openerp/http.py", line 294, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/opt/odoo/openerp/service/model.py", line 113, in wrapper
    return f(dbname, *args, **kwargs)
  File "/opt/odoo/openerp/http.py", line 291, in checked_call
    return self.endpoint(*a, **kw)
  File "/opt/odoo/openerp/http.py", line 754, in __call__
    return self.method(*args, **kw)
  File "/opt/odoo/openerp/http.py", line 387, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/addons/auth_oauth/controllers/main.py", line 93, in web_login
    response = super(OAuthLogin, self).web_login(*args, **kw)
  File "/opt/odoo/openerp/http.py", line 387, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/addons/auth_signup/controllers/main.py", line 38, in web_login
    response = super(AuthSignupHome, self).web_login(*args, **kw)
  File "/opt/odoo/openerp/http.py", line 387, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/addons/web/controllers/main.py", line 508, in web_login
    uid = request.session.authenticate(request.session.db, request.params['login'], request.params['password'])
  File "/opt/odoo/openerp/http.py", line 903, in authenticate
    uid = dispatch_rpc('common', 'authenticate', [db, login, password, env])
  File "/opt/odoo/openerp/http.py", line 108, in dispatch_rpc
    result = dispatch(method, params)
  File "/opt/odoo/openerp/service/common.py", line 26, in dispatch
    return fn(*params)
  File "/opt/odoo/openerp/service/common.py", line 38, in exp_authenticate
    return res_users.authenticate(db, login, password, user_agent_env)
  File "/opt/odoo/openerp/addons/base/res/res_users.py", line 464, in authenticate
    uid = self._login(db, login, password)
  File "/opt/odoo/addons/auth_ldap/users_ldap.py", line 258, in _login
    entry = ldap_obj.authenticate(conf, login, password)
  File "/opt/odoo/addons/auth_ldap/users_ldap.py", line 99, in authenticate
    filter = filter_format(conf['ldap_filter'], (login,))
  File "/usr/share/pyshared/ldap/filter.py", line 55, in filter_format
    return filter_template % (tuple(map(escape_filter_chars,assertion_values)))
TypeError: not all arguments converted during string formatting