Undefined index: ratings_score …/wp-postratings.php on line 994

when ever you expect something to be an array, it’s good practice to check to see if it is first before proceeding. so the new code might read like this:

if(is_null($post_ratings_data)) {
    $post_ratings_data = get_post_custom($post_id);
    if ( is_array( $post_ratings_data['ratings_users'] ) ) {
        $post_ratings_users = intval($post_ratings_data['ratings_users'][0]);
        $post_ratings_score = intval($post_ratings_data['ratings_score'][0]);
        $post_ratings_average = floatval($post_ratings_data['ratings_average'][0]);
    }
}