hum I think I find a small fix. but Iam not sure if its good or not but it working for me.

change class Zend_View_Smarty implements Zend_View_Interface

by class Zend_View_Smarty extends Zend_View_Abstract {

and add

protected function _run()
{
include func_get_arg(0);
}

to your Zend_View_Smarty class.