no old images show up in media library after migration

I migrated a lot of articles to another WP-installation by using the xml export feature and importing this file into the new system. I also migrated the uploads directory to the new location via ftp. After that I changed all paths in the articles via sql

UPDATE wp_posts SET post_content = replace(post_content, ‘http://www.old-domain.com’, ‘http://www.new-domain.com’);

The old images show up in the posts fine after doing that, but they do not appear in the media library at all. If I upload new images, the appear fine in the article, go to the correct folder /wp-content/uploads/2009/10/ and sho up in the media library, but all my old media do not show up.

What can I do to get them back into the media library?

I used the search but that did not come up with any solutions (but maybe my search terms were suboptimal).

Any help would be appreciated.