Wordpress - Weird post template issue

Im using the example from the wordpress site to add new post type, im using wp3.2.1, which is as below

// Add custom post type for the case studies
add_action( 'init', 'create_casestudy_post_type' );
function create_casestudy_post_type() {
    register_post_type( 'case_study',
        array(
            'labels开发者_JAVA技巧' => array(
                'name' => __( 'Case Studies' ),
                'singular_name' => __( 'Case Studies' )
            ),
            'public' => true,
            'has_archive' => true,
            'rewrite' => array('slug' => 'case-studies')
        )
    );
}

This code i have put in the functions.php file in my themes directory.

The problem is when i try and view the URL, it returns a 404 page not found ... im using single-case_study.php for the page template, but it just 404's all the time.

My permalinks are set to /%category%/%postname%/ in the custom structure.

Any help? .. this is really bugging me out

Cheers

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You can use Custom Post Type UI plugin to create a custom post type.