The fault exception handler registered in the constructor fails to output anything (resulting inempty pages) because fault() is designed to return the DomDocument instead. Suggest to register an separate echoing handler for uncaught exceptions only.

    /**
     * Constructor
     */
    public function __construct()
    {
        set_exception_handler(array($this, "echoFault"));
        $this->_reflection = new Zend_Server_Reflection();
    }

    /**
     * echo exception document
     *  
     * registered handler when all else fails
     * 
     * @param string|Exception $fault Message
     * @param int $code Error Code
     * @return DOMDocument
     */

    public function echoFault($exception = null, $code = null)
    {
        echo $this->fault($exception,$code)->saveXML(); 
    }