Kohana: Undefined index, if not

I am using Kohana 3.1 and I am getting a very strange error. It seems that Kohana's POH handler thinks that there is an undefined index when it's not there.

Inside the controller class:

$post = $this->request->post();
var_dump(isset($post['jid'])); //true
$jid = $post['jid']; //Undefined Index error.

If I really use it $post['jid'], it works fine, but annoying so that there is no way to assign it to a more convenient variable. Does anyone know what might cause this?

ErrorException [ Notice ]: Undefined index: jid
84       $jid = $post['jid'];

var_dump of $ post:

array(4) { 
    ["jid"]   => string(1) "7" 
    ["topic"] => string(5) "Test1"
    ["entry"] => string(14) "CHECK ONE TWO" 
    ["enter"] => string(4) "POST" 
}