无法使用正确的用户名和密码登录Django管理员

我已经部署在Django应用程序DigitalOcean使用ngnix，gunicorn和Postgresql数据库。一切运行正常，当我运行时python manage.py syncdb，我可以创建一个很好地填充数据库的用户。

我遇到的问题是，当我尝试登录Django管理界面时，系统提示我使用了错误的用户名和/或密码。我很确定凭据是正确的，因为我尝试过多次设置数据库。

关于Django为什么认为我输入了错误的用户信息的任何想法？

谢谢！

SETTINGS.py看起来像

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(__file__))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.6/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'XXXXXXXXXXXXXXX'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

TEMPLATE_DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'django.contrib.admin',
)

MIDDLEWARE_CLASSES = (
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
)

ROOT_URLCONF = 'qvido.urls'

WSGI_APPLICATION = 'qvido.wsgi.application'


# Database
# https://docs.djangoproject.com/en/1.6/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'mydbname',
        'USER': 'user',
        'PASSWORD': 'pass!',
        'HOST': 'localhost',
        'ROOT': '',
    }
}

# Internationalization
# https://docs.djangoproject.com/en/1.6/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.6/howto/static-files/

STATIC_ROOT = '/webapps/django-env/static/'

STATIC_URL = '/static/'

WSGI.py看起来像

import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "qvido.settings")

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

编辑

好的，我也尝试这样做python manage.py dbshell，select * from auth_user;我看到了我创建的用户，但仍然无法使用它登录。这么奇怪。