如何设置默认语言django-modeltranslation

Question

我使用django-modeltranslation它运作良好，但我有问题默认语言不工作，网站加载其他语言

我的settings.py

LANGUAGE_CODE = 'ka'

gettext = lambda s: s 

LANGUAGES = [
    ('ka', gettext('Georgian')),
    ('en', gettext('English')),
    ('ru', gettext('Russian')),
]

MODELTRANSLATION_DEFAULT_LANGUAGE = 'ka'
MODELTRANSLATION_LANGUAGES = ('ka','en','ru')
MODELTRANSLATION_FALLBACK_LANGUAGES = ('ru','en')
USE_I18N = True
USE_L10N = True

urls.py config

urlpatterns = patterns('',

url(r'^app/', include('app.urls')),
# url(r'^i18n/', include('django.conf.urls.i18n')), # i tried this too
url(r'^set_language/$', 'django.views.i18n.set_language',{},name='set_language'),

)

如何解决这个问题？解决方案是什么？