Custom Taxonomy archive template with CustomPress

Hi

I have been trying to add a custom archive template to a Custom taxonomy integrated with a custom Post Type both created with CustomPress.

I am running Wordpress and buddypress site here http://willypointkids.com/

I created the CPT called Partners, it has two template file, archive-partners.php and single-partners.php
http://willypointkids.com/partners/
http://willypointkids.com/partner/caribou-baby/. All good so far.

Now I have created a custom taxonomy called partners_categories. I have picked the slug partner/category to trick the rewrite url rules so I get the following
http://willypointkids.com/partners/category/store/

Now my problem is that it looks like the default archive template and I would like to look like the archive-partners.php template. How can I do this? I have try taxonomy-partners.php or taxonomy-partners_categories but allways see the default archive.php template!?...

Thanks in advance for your help,
T.