Im trying to utilize the Zend_Session_Namespace functionality and I can't get this thing to go...any help would be appreciated

My bootstrapper has the following...

$idSession = new Zend_Session_Namespace('ID_Session');
$idSession->_myid= "5"

Now in my IndexController I try and reset this id like so...

$idSession = new Zend_Session_Namespace('ID_Session');
$idSession ->_myid= "10";

Then in my view I display this...and it always comes up as 5...so its not modifying the session variable...im assuming its "read-only"? How can I get it so I can modify this value...

Thanks