If the permission change that Mark suggested fixed your problem then you can ignore my comment.
When I visit your test page I am seeing some of the content. I see a list of messages that shows the subject, author and post date. The message body is not currently showing, which might have been intentional. The reason the message body is not showing is because the "Number of words in body" was set to 0 when you created the Activecast code in the Admin. If you do want the body to show then you can just leave the "Number of words in body" setting empty when you create the code in the Admin or set it to some value which will be used to truncate the number of words in the body.