gistfile1.html

  <div id="fb_comments">
    <fb:comments title="Comment Test - Social Plugin" numposts="5" 
          xid="set_publish_feed_to_false_demo" simple="1" 
          width="510" reverse="false" publish_feed="false">
     </fb:comments>
  </div>

  <div id="fb-root"></div>

  <script>
    var timer; 

    window.fbAsyncInit = function() {
      FB.init({appId: '80529a5b4455847bc31b1125b0e92cc2', status: false, cookie: false, xfbml: true});
    };

    (function() {
      var e = document.createElement('script'); e.async = true;
      e.src = document.location.protocol +
        '//connect.facebook.net/en_US/all.js';
      document.getElementById('fb-root').appendChild(e);
      timer = setInterval(updateComments, 1000);
    }());

    function updateComments() {
        var iframe_src = $('#fb_comments iframe').attr('src')
        if(iframe_src.indexOf('comments.php') > 0) {
          clearInterval(timer);
          $('#fb_comments iframe').attr('src', iframe_src + "&publish_feed=false");
        }
    }
  </script>