Trouble when using route config in codeigniter 2.1

[eluser]Unknown[/eluser]
Hallo everyone. I have trouble when using routing. I'm going to build multilanguage aplication in codeigniter 2.1. I tried this code in config/route.php:

Code:

$route['^(id|en)/(.+)$'] = "$2";
$route['^(id|en)$'] = $route['default_controller'];

when i try to access http://localhost/myapp/index.php/id/welcome it's not work, just 404 Page Not Found. I have tried in codeigniter 2.0.3 it just OK. why this happened?

Is there any change when using routing in codeigniter 2.1? What the best way to solf my problem. Thanks