Something wrong with Models Cache and custom PDO options

Hi all.

I have mysql table catalog(id, title, status) and simple application with one model

$di = new \Phalcon\DI\FactoryDefault();

$di->set(
    'modelsMetadata', function() {
        return new \Phalcon\Mvc\Model\MetaData\Apc(
            array(
                "lifetime" => 86400,
                "prefix" => "metadata"
            )
        );
    }
);

$di->set(
    'modelsCache', function() {
        $frontCache = new \Phalcon\Cache\Frontend\Data(
            array(
                "lifetime" => 600,
                "prefix"   => "cache"
            )
        );
        return new \Phalcon\Cache\Backend\Apc($frontCache);
    }
);

$di->set(
    'db', function() {
        return new \Phalcon\Db\Adapter\Pdo\Mysql(
            array(
                'host' => 'localhost',
                'username' => 'login',
                'password' => 'pass',
                'dbname' => 'db',
                'charset' => 'utf8',
                'options' => array(
                    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,
                    PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
                )
            )
        );
    }
);

class Catalog extends \Phalcon\Mvc\Model
{

}
echo 'example page' . PHP_EOL;
$categories = Catalog::find(array("status = 1", 'cache' => array('key' => 'my_cache_key', 'lifetime' => 120)));
echo 'total count: ' . count($categories) . PHP_EOL;
foreach ($categories as $category) {
    print_r($category->toArray());
}

when i run it first (with empty cache) i see: "example page total count: XX" with empty foreach cycle, but next runs everything works good.

After several debug time i've found the reason. it's

PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,

Can anybody tell me why and how to fix it?

ps: PHP Version 5.3.10-1ubuntu3.8/phalcon 1.2.3/ pdo_mysql 5.5.32