Getting 403 Forbidden when using Oauth2.0 - django

Question

I am using "Oauth2.0" to access YouTube data API.
the site is hosted on a Django platform, its address is http://listplay1.pythonanywhere.com/
Every time I'd like to authorize myself I refresh the access token and use the new one to get access.
Most of the time it works flawlessly but sometimes I get 403 Forbidden error. when I do the same from the terminal on my pc it works always
Can anyone have an idea in regards to how is it happening only part of the time and more importantly, how to fix it?
Thanks a mill in advance,
*the $$$ parts are hidden on purpose of course.
def auth():
h={'Host':'accounts.google.com','Content-Type':'application/x-www-form-urlencoded','X-GData-Key':'key=$$$'}
content={'client_id':'567194806765-r1pdllkji4tpgv1dc0a9ihrvh0hocoik.apps.googleusercontent.com','client_secret':'$$$','refresh_token':'$$$','grant_type':'refresh_token'}
p=urllib.urlencode(content)
r = requests.post('https://accounts.google.com/o/oauth2/token', data=p,headers=h)
token=r.json().values()[0]
credentials = AccessTokenCredentials(token,'my-user-agent/1.0')
return build(YOUTUBE_API_SERVICE_NAME, YOUTUBE_API_VERSION,http=credentials.authorize(httplib2.Http()))
and the error
Environment:
Request Method: GET
Request URL: http://listplay1.pythonanywhere.com/thanks/
Django Version: 1.3.7
Python Version: 2.7.5
Installed Applications:
['django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'django.contrib.admin',
'main.myapp']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware')
Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
111. response = callback(request, *callback_args, **callback_kwargs)
File "./main/myapp/views.py" in thanks
64. Pid=create_playlist(YT="",title=TITLE)
File "/home/LISTPLAY1/LISTPLAY/listplay.py" in create_playlist
261. YT=auth()
File "/home/LISTPLAY1/LISTPLAY/listplay.py" in auth
257. return build(YOUTUBE_API_SERVICE_NAME, YOUTUBE_API_VERSION,http=credentials.authorize(httplib2.Http()))
File "/home/LISTPLAY1/LISTPLAY/oauth2client/util.py" in positional_wrapper
132. return wrapped(*args, **kwargs)
File "/home/LISTPLAY1/LISTPLAY/apiclient/discovery.py" in build
192. resp, content = http.request(requested_url)
File "/home/LISTPLAY1/LISTPLAY/oauth2client/util.py" in positional_wrapper
132. return wrapped(*args, **kwargs)
File "/home/LISTPLAY1/LISTPLAY/oauth2client/client.py" in new_request
490. redirections, connection_type)
File "/usr/local/lib/python2.7/dist-packages/httplib2/__init__.py" in request
1570. (response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey)
File "/usr/local/lib/python2.7/dist-packages/httplib2/__init__.py" in _request
1317. (response, content) = self._conn_request(conn, request_uri, method, body, headers)
File "/usr/local/lib/python2.7/dist-packages/httplib2/__init__.py" in _conn_request
1252. conn.connect()
File "/usr/local/lib/python2.7/dist-packages/httplib2/__init__.py" in connect
1018. sock.connect((self.host, self.port))
File "/usr/local/lib/python2.7/dist-packages/httplib2/socks.py" in connect
424. self.__negotiatehttp(destpair[0], destpair[1])
File "/usr/local/lib/python2.7/dist-packages/httplib2/socks.py" in __negotiatehttp
390. raise HTTPError((statuscode, statusline[2]))
Exception Type: HTTPError at /thanks/
Exception Value: (403, 'Forbidden')