function stickies_and_old($posts)
{
    if (is_category() || is_tag() )
        $posts = sort_stickies($posts);
    else
        return $posts;

    return $posts;
}

add_filter('the_posts','stickies_and_old');

function sort_stickies($posts)
{
    $sposts = array();
    $stickies = get_option('sticky_posts');


    foreach($posts as $post_index => $dpost):
        if (in_array($posts[$post_index]->ID,$stickies)) :
            $sposts[] = $dpost;
            unset($posts[$post_index]);
        endif;
    endforeach;
    $posts = array_merge($sposts,$posts);
    return $posts;
}