Custom Post type forgetting data

In the function hooked onto save_posts you should make sure that you check that the action wasn’t triggered by an auto-save routine. I suspect that the reason why the post ‘forgets’ the data is that the post auto-saves, and updates the post-meta with blank data.

To do this:

function save_details($post_id){
    //Make sure you check this isn't an autosave.
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
         return;

    update_post_meta($post_id, "media_meta", $_POST["media_meta"]);
    update_post_meta($post_id, "highlights_meta", $_POST["highlights_meta"]);
    update_post_meta($post_id, "main_meta", $_POST["main_meta"]);
    update_post_meta($post_id, "tabbed_meta", $_POST["tabbed_meta"]);
}

I’ve had a quick glance at the tutorial. It seems to ignore best practice and security checks such as the following:

1. The function hooked on save_posts is given the argument $post_id
   (the post ID). You should use this rather than global $post.
2. Prefix your functions. save_details is very generic, and if the WordPress core or another plug-in uses that function name, it’ll crash your blog. This is particularly important for plugin developers. Prefix it with something unique: my_name_save_details. Same goes for the other functions.
3. Check user permissions. Use current_user_can to verify that a user is allowed to be editing the post.
4. Uses nonces. In your metabox, add a nonce and verify it in my_name_save_details. This checks the data you’re adding to your database really came from your metabox.(See Codex)
5. Perform other checks. save_posts fires every time a post or page is saved/updated, but you only really want to be altering posts of your custom post type. It’s not essential, but removes the possibility of upsets further down the line. You can use get_post_type to help with this.