This goes for both FF and IE
Depending on your callback url - if your callback url is
http://yoursite.com/ then to use this mod you need to go to
http://yoursite.com and vice versus.
On my site I have
http://www.globalhockeynetwork.com/ as the callback url so if I go to my site using
http://www.globalhockeynetwork.com everything works.
If I use
http://globalhockeynetwork.com - I get the error in the attachment.
Check out
this page to set rewrites in your .htaccess file to automatically direct to one or the other