query_posts & custom taxonomies

I created a custom post type and custom taxonomy for it. I’m trying to query posts from the post type and by the custom taxonomy.

For instance, I’dlike to query posts from the “Directors” category in this custom taxonomy. Looking at the url for this taxonmy, I see it has a tag_ID of 22.

...edit-tags.php?action=edit&taxonomy=positions&tag_ID=22&post_type=biography

I’m using the following code to query:

<?php query_posts('post_type=biography&tag_ID=22'); if ( have_posts() ) : ?>

However, my results are not what I’m looking for. Any help would be appreciated.