Eu sou novo no Django. Eu instalei o Django usando o easy_install (em um Mac) e o plugin PyDev Django para eclipse. Eu segui os procedimentos padrão para criar um novo projeto PyDev Django. Quando tento executar o projeto como PyDev: Django, recebo o seguinte erro.

Validating models...

RuntimeError: maximum recursion depth exceeded

Eu também tentei adicionar a seguinte linha no manage.py, mas é inútil.

sys.setrecursionlimit(2000)

Aqui está o stacktrace parcial.

Unhandled exception in thread started by <bound method Command.inner_run of    <django.contrib.staticfiles.management.commands.runserver.Command object at 0x10e2*****>>
Traceback (most recent call last):
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/core/management/commands/runserver.py", line 92, in inner_run
self.validate(display_num_errors=True)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/core/management/base.py", line 280, in validate
num_errors = get_validation_errors(s, app)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/core/management/validation.py", line 35, in get_validation_errors
for (app_name, error) in get_app_errors().items():
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/loading.py", line 166, in get_app_errors
self._populate()
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/loading.py", line 72, in _populate
self.load_app(app_name, True)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/loading.py", line 96, in load_app
models = import_module('.models', app_name)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/contrib/auth/models.py", line 370, in <module>
class AbstractUser(AbstractBaseUser, PermissionsMixin):
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/base.py", line 213, in __new__
new_class.add_to_class(field.name, copy.deepcopy(field))
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/base.py", line 265, in add_to_class
value.contribute_to_class(cls, name)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/fields/__init__.py", line 257, in contribute_to_class
cls._meta.add_field(self)
File "/Library/Python/2.7/site-packages/Django-1.5-py2.7.egg/django/db/models/options.py", line 179, in add_field
self.local_fields.insert(bisect(self.local_fields, field), field)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 56, in <lambda>
'__lt__': [('__gt__', lambda self, other: other < self),
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 56, in <lambda>
'__lt__': [('__gt__', lambda self, other: other < self),
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 56, in <lambda>
'__lt__': [('__gt__', lambda self, other: other < self),
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 56, in <lambda>
'__lt__': [('__gt__', lambda self, other: other < self),

O que estou fazendo de errado?