Cannot use Zend_Session_Namespace in SocialEngine

I am trying to use Zend_Session_Namespace to help me with the task of changing a user's password. To this purpose, I need to store some values of their GET request when they first visit the reset page. I'd like to do that with Zend_Session_Namespace. Then, I want to update the user's password in their post request (from the same page) using the values I saved in Zend_Session_Namespace. The problem is the values saved in Zend_Session_Namespace are null when I access them. However, I can still do the job with the typical $_SESSION variable. Does anyone know where I'm wrong? Am I missing some tip about using Zend_Session_Namespace? Do I need to use Zend_Registry or something to that effect?

My code for the action is as follows:

/**
 * This handles password change
 */
public function changepasswordAction() {        
    $passwordForm = new Advancedsms_Form_ChangePassword();
    $this->view->form = $passwordForm;

    //If it is NOT post, the user has to provide recovery code and phone number
    if(!$this->getRequest()->isPost()) {
        $phone = filter_input(INPUT_GET, 'phone', FILTER_SANITIZE_URL);
        $recovery = filter_input(INPUT_GET, 'recovery', FILTER_SANITIZE_URL);
        $this->session= new Zend_Session_Namespace('RecoverySession');
        $this->session->phone= $phone;
        $this->session->recoveryCode = $recovery;   
        print_r($this->session);
        $_SESSION['phone'] = $phone;
        $_SESSION['recovery'] = $recovery;
    }
    if($this->getRequest()->isPost()) {            
        $params = $this->getRequest()->getParams();
        print_r($params);
        echo 'phone: ' . $this->session->phone .PHP_EOL;
        echo 'recovery: ' . $this->session->recoveryCode . PHP_EOL;
        echo $_SESSION['phone'] . ',' . $_SESSION['recovery'];
    }
}

You need to move this line:

$this->session= new Zend_Session_Namespace('RecoverySession');

to before the if statements. At the moment your echo 'phone: ' . $this->session->phone line will do nothing because $this->session is not set on POST requests.

You should always write PHP code with the PHP error level at its most verbose, which would show warnings for issues like this.