I recently migrated one of my WordPress installations to a new server. I backed up my database, copied the wp-content folder to my computer, uploaded it to the new server with the WordPress files already in place, and restored my database to the new server. Everything works fine, except that it seems the data about uploads didn't make the transition. For example, sizing data about images seems to be missing, since images are not shrunk to fit the page in single page view, and thumbnails are not shown in the Manage Uploads area in the admin panel. How can I make sure that upload data migrates with the rest of my WordPress data?