If you have visited the old pages of this site following links, even links within the site, you would have noticed a ton of 404 (Page not found) errors.
As I've said previously, I did not switch over all the old pages to the new Drupal installation, so this has nothing to do with Drupal.
This is due to one really annoying 'feature' of Movable Type - URLs are not kept in the database. (Since it's not in the database, it doesn't make it to the text backup file either. Incidentally this also applies to Typepad.)