PHx + CDATA, problems

 $e= & $modx->Event;
switch ($e->name) {
    case "OnWebPagePrerender":    
    $text = $modx->documentOutput;
    // search and replace empty tags in document    
         $modx->documentOutput = str_replace('].]',']]',$modx->documentOutput);
        break;    

        return; // stop here - this is very important. 
        break;
}