Duplicate slugs… Fixing wp_posts

I installed Duplicate Post a while ago to facilitate the authors’ work. But I left the Duplicate Slug checkbox activated, which was an error, but it was unnoticed as we don’t use the slug in the URL. The problem appeared when I tried to automatically cross post the blog’s articles with a forum. The forum system is taking over post_name in the wp_posts table and we soon had conflicting URL on the forum.

I changed that now, but there still is a mess in wp_posts. Any idea how I could fix that?

The page I need help with: [log in to see the link]