If you are using custom Google Apps domains, make sure that the administrator of your domain has enabled the 'Google App Engine' service from the Google Apps dashboard. I previously got the 'not authorized' message and solved this issue by doing the above.
-- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
