Calling to Django webservice from Android results in OpenID in progress message

I am trying to build a website, with accompanying app.
The users should be able to log in using their OpenID and then start using the site, or app. And obviously, since they sign into both using their OpenID they can start where they left off.
Everything works in the browser.
In the Android app it gets a bit hairier. The solution I am trying to build will log the user in, using a WebView.
Then grab the required cookies from this WebView and reuse those with the next requests.
Currently I am grabbing the sessionid only. Which seems the only required cookie, when I try it in Chrome with the developer tools.
However, when I pass this sessionid allong with the request, I get as a result, the page which says OpenID transaction in progress.

I only grab this sessionid after the user returns on my own webpage again. So normally the OpenID transaction should be over.
Could anybody help me out?