Drupal 6 nodes not appearing in content list after migration

I've copied a Drupal installation from the production server to a development site to do some additional work. It all seems to be set up OK, other than the fact that nodes of one particular content type do not appear in the content list 开发者_如何转开发or at their node/nid or aliased urls, I just get 'page not found'.

To migrate, I copied the database directly, moved over the files and updated settings.php. As I mentioned, the rest of the site works fine, its just missing lots of nodes which ARE in the database, but not picked up by Drupal, even after refreshing the cache, running cron.

Any ideas appreciated! Cheers

Are all your nodes missing? Were you using clean urls on your production server? If so, are these enabled on your development site?