title: og:image content is recognized as a valid URL but is unable to retrieve image
body: <p>We recently moved servers and I've been having this problem since. </p>
  
  <p>I tried parsing this <a href="http://developers.facebook.com/tools/debug/og/object?q=http%3A%2F%2Fwww.riotengine.in%2F2012%2F05%2F12%2Fyou-and-i-owe-this-man-carroll-shelby%2F" rel="nofollow">url1</a> in the Facebook Debug tool, and the thumbnail retrieved using the content of the og:image tag is displayed fine, but it won't display when I 'like' the story and it appears in my profile . This was a story posted before switching servers. </p>
  
  <p>Now when I try parsing this <a href="http://www.riotengine.in/2012/05/19/porsche-918-spyder-is-on-the-road/" rel="nofollow">url2</a> in the Facebook Debug tool, the thumbnail is not retrieved and with previous case the thumbnail won't display in my profile when I like this story. This is a story posted after switching servers.</p>
  
  <p>The funny thing I try repeating these actions and the thumbnail does pop up randomly. </p>
  
  <p>How does Facebook retrieve the image from my server? Does the problem have something to do with how this is done?</p>