Facebook IFrame Canvas Flash Issue in Internet Explorer

app.rb

headers 'Content-Type' => "text/html;charset=utf-8",
  'Last-Modified' => Time.now.httpdate,
  'P3P' => 'CP="CAO PSA OUR"',
  'X-UA-Compatible' => 'IE=edge'


#Might not hurt either in the html header: <meta http-equiv="X-UA-Compatible" content="IE=7" />

Description.text

In Internet Explorer there was an issue where the iframe/canvas embed for a Facebook App would cause flashing as the app redirected to itself over and over as it was blocking any sort of cookies set from an external url...

Source of final AHA:
http://duanesbrain.blogspot.com/2007/11/facebook-ie-and-iframes.html


View the Page's Privacy Policy in Internet Explorer and you should see external cookies blocked for your app that is hosted elsewhere.

Solution: 
Set the headers properly! (Or check if you aren't loading a file properly like Duane's solution).

PHP: 
header('P3P: CP="CAO PSA OUR"')

Sinatra/Ruby below