custom taxonomy in custom post link

Hello
i’m trying to make the rewrite of custom post type “news” in custom taxonomy “blog” like this :

site.com/news/term-title/post-title

tried this function:

function filter_post_type_link($link, $post)
{
    if ($post->post_type != 'news')
        return $link;

    if ($cats = get_the_terms($post->ID, 'blog'))
        $link = str_replace('%terms%', array_pop($cats)->slug, $link);
    return $link;
}
add_filter('post_type_link', 'filter_post_type_link', 10, 2);

it make the structure like this :
site.com/term-title/post-title
without the slug and also not found 404 for post and term pages!

Any help, or a quick tut on how to display the desired structure and make it work would be helpful.

Thanks