The titles for inclusion in an edition get doubled up

I have just installed ePublish (very interesting module) on a small test bed running Drupal 4.6.2, and find that whenever I add an article (book page) to an edition from the list, when I return to the list it appears to have been added two times to the list - so now there are three articles appearing in the list with the same title. If I add the title to another publication, then there are 5 articles with the same title in the list, and so on