Widget breaks category taxonomy page

Hi, I’m implementing the widget like this on a portfolio page page:

<?php the_widget('cat_tag_filter','title=Filter Stoves:&button_title=Filter&cat_list_label=By manufacturer:&category_tax=portfolio_cats&all_cats_text=All Manufacturers&tag_list_label=Of type:&all_tags_text=Any Type'); ?>

I am using this widget on a portfolio page to limit posts by category, once the user has selected a category they are taken to that category page but the posts don’t load as I’m also loading the widget on that page. It works fine when the widget is removed from the category page. Any suggestions on what could be causing this conflict?

Edit: The posts load if I just have:

<?php the_widget('cat_tag_filter'); ?>

On the category page, so it seems its just the $args that are causing the problem. Any suggestions?

Cheers

http://wordpress.org/extend/plugins/cat-tag-filter-widget/