usually in a xhr action I use this code
$this->_helper->layout->disableLayout();
$this->_helper->viewRenderer->setNoRender(true);
$response = $this->getResponse();
$response->setHeader('Content-type', 'application/json', true);
return $response->setBody(Zend_Json::encode($data));
I'm wondering if it need utf-8 encoding like this
$response->setHeader('Content-type', 'application/json;charset=UTF-8', true);