title: Facebook not showing og:image thumbnail in MSIE9 on subsequent shares
body: <p>I'm having a bizarre problem with Facebook. When I share my content in MSIE 9, it successfully loads the thumbnail the first time I share a URL, but if I share it again, the thumbnail does not load (and never loads again). It just shows their animated "loading" image for several seconds, then that disappears and so do the thumbnail options.</p>
  
  <p>You can see this yourself by clicking these Facebook share links in MSIE 9.</p>
  
  <p><a href="http://www.facebook.com/sharer/sharer.php?u=https%253A%252F%252Fsparkengine.call2action.com%252Fsparks%252F5186%252Flive" rel="nofollow noreferrer">Example 1</a>
  <a href="http://www.facebook.com/sharer/sharer.php?u=https%253A%252F%252Fsparkengine.call2action.com%252Fsparks%252F5175%252Flive" rel="nofollow noreferrer">Example 2</a></p>
  
  <p>The same sharing functionality works fine in other browsers, and sharing other pages (e.g. Youtube videos) from the same MSIE 9 works fine every time.</p>
  
  <p>Running <a href="https://developers.facebook.com/tools/debug" rel="nofollow noreferrer">Facebook's debugger</a> does not resolve the problem, nor does it report any problems with the OpenGraph tags on my page. It even shows the thumbnails in question.</p>
  
  <p>Looking at the Network tab of the Developer Tools in Facebook shows that the thumbnail image is being loaded each time I share the content.</p>
  
  <p><strong>Update</strong></p>
  
  <p>I've found that MSIE 9 will display the image under the following conditions:
  - if I have the image in my cache already
  - if the browser doesn't make a request to the server to the safe_image.php URL where the image comes from.</p>
  
  <p>I've been messing around with this test page: <a href="http://www.facebook.com/sharer/sharer.php?u=http://c2a-v3-staging.s3.amazonaws.com/sparks%2Fspark_5079%2Findex_test.html" rel="nofollow noreferrer">http://www.facebook.com/sharer/sharer.php?u=http://c2a-v3-staging.s3.amazonaws.com/sparks%2Fspark_5079%2Findex_test.html</a></p>
  
  <p>I cannot load the image if I refresh the page, as that makes a request to the server for safe_image.php. It doesn't matter whether the response is a 200 or a 304, the image does not display. However, if I then go to the location bar and press enter, that's a "navigate" event instead of a "refresh", no request is made for the image, and it is displayed (after being loaded from the cache).</p>
  
  <p>I've tried serving the image from another domain, adding the og:image:secure_url tag, having Facebook crawl the HTML on a different domain, and this is the best I can do so far. Unfortunately, it's pretty useless because it means the first share from any user will never work right.</p>