$GLOBALS['facebook_config']['debug'] = true;

This will actually insert some script code to the header of every page served, in order to render the tracking code, if there is something to render:



<script type="text/javascript">
var types = ['params', 'xml', 'php', 'sxml'];
function getStyle(elem, style) {
  if (elem.getStyle) {
    return elem.getStyle(style);
  } else {
    return elem.style[style];
  }
}
function setStyle(elem, style, value) {
  if (elem.setStyle) {
    elem.setStyle(style, value);
  } else {
    elem.style[style] = value;
  }
}
function toggleDisplay(id, type) {
  for (var i = 0; i < types.length; i++) {
    var t = types[i];
    var pre = document.getElementById(t + id);
    if (pre) {
      if (t != type || getStyle(pre, 'display') == 'block') {
        setStyle(pre, 'display', 'none');
      } else {
        setStyle(pre, 'display', 'block');
      }
    }
  }
  return false;
}
</script>

The catch is that the script code is always inserted, even if there were no facebook api calls involved. So the script code renders at the top for every page, also when its a JSON AJAX response. This means of course that the JSON will not be parsed on the browse – not good.

I now use other tools to track what requests are being sent back and forth instead between my application and facebook.