i use this configuration, try this lines
settings.py
SITE_ROOT = os.path.dirname(__file__)
THUMBNAIL_DEBUG = True
MEDIA_ROOT = os.path.join(SITE_ROOT, 'media')
MEDIA_URL = '/media/'
url.py
from django.conf import settings
media_root = getattr(settings, 'MEDIA_ROOT', '/media')
urlpatterns += patterns('',
url(r'^media/(?P<path>.*)$','django.views.static.serve',
{'document_root': media_root})
)