Adding custom taxanomy to custom posttype URL

Hi Everybody,

At the moment i’m using a wonderful plugin named Custom Post Type UI and doing (for 90%) the work perfectly.

It allows me to make custom post types, taxanomies and automaticly? rewrites the URL.

But my problem is:

I’ve created a post type, named ‘books’ and a taxanomy named ‘author’ and added a book named ‘Bookie1’.

I want the author name( example ‘Martin’) in the url when i’m navigating to the ‘Bookie1’, so the URL would be:
books/martin/bookie1

My current URL is:
books/bookie1

It works with the standard category, but not the custom one. Any ideas how i can ‘tweak’ the custom taxanomy into the URL?