google-app-engine-django loaddata doesn't seem to work, not datastore on filesystem

Question

I'm working on a Django AppEngine application using the AppEngine Django helper (google-app-engine-django), and I'm trying to create some initial data to load into my datastore. Here's my directory structure:

.
./__init__.pyc
./index.yaml
./api
./api/__init__.py
./api/models.py
./api/views.py
./api/urls.py
./appengine_django
./manage.py
./urls.pyc
./static
./static/css
./static/img
./templates
./templates/index.html
./__init__.py
./.google_appengine
./settings.py
./app.yaml
./main.py
./fixtures
./fixtures/initial_data.json
./urls.py

The data I'm trying to load is in fixtures/initial_data.json:

[
  { "model" : "api.models.PaymentMethod",
    "fields" : {
    "ptype": "Credit",
    "org": "MasterCard",
    "acct": "0123456789abcdef"
    }
  }
]

When I try to run '$./manage.py loaddata intial_data' or '$./manage.py flush', I get the following:

/opt/google/google_appengine/google/appengine/api/datastore_file_stub.py:40: DeprecationWarning: the md5 module is deprecated; use hashlib instead
  import md5
/opt/google/google_appengine/google/appengine/api/memcache/__init__.py:31: DeprecationWarning: the sha module is deprecated; use the hashlib module instead
  import sha
WARNING:root:Could not read datastore data from /tmp/django_myapp.datastore
WARNING:root:Could not read datastore data from /tmp/django_myapp.datastore

After doing this, I do '$./manage.py runserver' and check /_ah/admin/datastore and find nothing there. I'm not sure I understand why this doesn't work as expected.