Проблема с Django MongoDB

мое приложение django запускается с mysql, но когда я пытаюсь использовать mongodb, то показываю thie error

Traceback (most recent call last):
  File "manage.py", line 14, in <module>
    execute_manager(settings)
  File "/home/abdullah/django-trunk/django/core/management/__init__.py", line 442, in execute_manager
    utility.execute()
  File "/home/abdullah/django-trunk/django/core/management/__init__.py", line 379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/abdullah/django-trunk/django/core/management/base.py", line 191, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/home/abdullah/django-trunk/django/core/management/base.py", line 209, in execute
    translation.activate('en-us')
  File "/home/abdullah/django-trunk/django/utils/translation/__init__.py", line 106, in activate
    return _trans.activate(language)
  File "/home/abdullah/django-trunk/django/utils/translation/trans_real.py", line 191, in activate
    _active.value = translation(language)
  File "/home/abdullah/django-trunk/django/utils/translation/trans_real.py", line 180, in translation
    default_translation = _fetch(settings.LANGUAGE_CODE)
  File "/home/abdullah/django-trunk/django/utils/translation/trans_real.py", line 157, in _fetch
    app = import_module(appname)
  File "/home/abdullah/django-trunk/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/home/abdullah/django-trunk/django/contrib/admin/__init__.py", line 3, in <module>
    from django.contrib.admin.helpers import ACTION_CHECKBOX_NAME
  File "/home/abdullah/django-trunk/django/contrib/admin/helpers.py", line 2, in <module>
    from django.contrib.admin.util import (flatten_fieldsets, lookup_field,
  File "/home/abdullah/django-trunk/django/contrib/admin/util.py", line 1, in <module>
    from django.db import models
  File "/home/abdullah/django-trunk/django/db/__init__.py", line 27, in <module>
    connection = connections[DEFAULT_DB_ALIAS]
  File "/home/abdullah/django-trunk/django/db/utils.py", line 82, in __getitem__
    conn = backend.DatabaseWrapper(db, alias)
  File "/usr/local/lib/python2.6/dist-packages/django_mongodb_engine-0.4.0-py2.6.egg/django_mongodb_engine/base.py", line 87, in __init__
    self.ops = DatabaseOperations(self)
  File "/usr/local/lib/python2.6/dist-packages/djangotoolbox-0.9.2-py2.6.egg/djangotoolbox/db/base.py", line 28, in __init__
    super(NonrelDatabaseOperations, self).__init__()
TypeError: __init__() takes exactly 2 arguments (1 given)

** Я установил все необходимые модули, но когда я хочу запустить сервер, покажите это сообщение