For Django 1.6: new test discovery plus reverse now does urlquote(). My base64 keys were padded with '=' and these got quoted when doing a reverse to generate the URL. So changed the test to look for a quoted version of the key. This will change the URLs sent to users, but I believe it will all be taken care of by Django.

tinyMCE.addI18n('en.autosave',{
restore_content: "Restore auto-saved content",
warning_message: "If you restore the saved content, you will lose all the content that is currently in the editor.\n\nAre you sure you want to restore the saved content?"
});