[Django]-Django SESSION_COOKIE_DOMAIN

In all likelihood, you are ending up with multiple sessionid cookies being sent. If you have a sessionid cookie with domain ‘example.com’ and another cookie with domain ‘.example.com’, Django will test only one of those sessionid values. I am unsure of how Django decides which sessionid value to test for validity.

Check your cookies in your browser (in FF, Tools -> Options -> Privacy -> Something about cookies) and see if they are correctly set. Search for your domain, and see if you have the sessionid cookie is set.

It might be a browser issue as Paul suggests. However, I’d be tempted to do some HTTP analysis with Firebug or Live HTTP Headers in Firefox. Is it trying to set the cookie correctly?