Twig and Namespaces

Hello, I'm having a hard time implementing Twig in my project MVC , I'm using namespaces, autoloader all that PSR-0 thing. I'd like your judah to implement because I'm almost freaking out. rs

public function render($file, $data = null){        
    require_once LIB . '/Twig/Autoloader.php';
    \Twig_Autoloader::register();               

    $loader = new \Lib\Twig_Loader_Filesystem('/path/to/templates');
    $twig = new Twig_Environment($loader, array(
        'cache' => '/path/to/compilation_cache',
    ));
}

This is my method that will render the template, so far I have the following error:

Exception: Controller Twig_Autoloader not found. in C:\UwAmp\www\system\engine\autoload.php