[Plugin: Query Multiple Taxonomies] Page change after selecting custom tax terms

Hello,

I’m using WP 3.1.3 and QMT 1.5 for developing a new site. Instead of the widget I use the following code on tag and category pages:

<?php
the_widget('Taxonomy_Drill_Down_Widget', array(
    'title' => '',
    'mode' => 'lists',
    'taxonomies' => array( 'post_tag','region' ) // list of taxonomy names
));
?>

If I go to the archive page of category 1 (www.domain.com/category/1) and select a term of the post tags in the QMT list, the queried posts perfectly show up on the same page.

However, if I (still on https://www.domain.com/category/1) select a custom taxonomy term such as Region A in the QMT list, the browser jumps to the archive page of Region A (www.domain.com/?category_name=1&region=a). It still shows the correct selection of posts belonging to category 1 as well as region A, however, it confuses users since I use different templates and titles for tag pages, category pages and taxonomy pages.

Does anyone know whether this occurence can be avoided? And if so, how? Many thanks for any help!

Andreas