Strange behavior model

I have this table:

CREATE TABLE IF NOT EXISTS `action_history` (
  `id` int(11) NOT NULL,
  `timestamp` int(11) NOT NULL,
  `action` enum('call','logout','in_game','reg') NOT NULL,
  UNIQUE KEY `id` (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

And this model:

use Phalcon\Mvc\Model\Behavior\Timestampable;

class ActionHistory extends \Phalcon\Mvc\Model {
    public $id;
    public $timestamp;
    public $action;

    public function getSource() {
        return 'action_history';
    }

    public function initialize() {
        $this->hasOne("id", "Users", "id", array(
            "alias" => "User"
        ));

        $this->addBehavior(new Timestampable(array(
            "beforeValidateOnCreate" => array(
                "field" => "timestamp"
            )
        )));
    }

    public function beforeValidateOnCreate() {
        $this->action = 'reg';
    }

    public function beforeValidate() {
        // just for testing thats validation not work
        $this->timestamp = time();
    }

}

And i have this troubles:

/** @var $user Users */
$ah = new ActionHistory();
$ah->user = $user; // store this var in field "user" in model, not as related id
$ah->id = $user; // -> fatal error on save by Users don't have __toString()
$ah->id = $user->id; // setted as string and converted in 0
$ah->id = (int) $user->id; // work!
// $ah->save() or $ah->create() don't have any differences

And even more: behavior or beforeValidate () do not fire at all (checked through xdebug), and immediately takes off gives an error "timestamp is required".

WTF?