Taxonomy Terms limit pagination on single template – cannot get it to work

Hi,
I’ve created a custom post type cc_porfolio which has the following taxonomy associated with it portfolio_cat – the portfolio items are them categorised using the the following custom terms theatre, opera, events..

I’ve set up the following code in fuctions to allow me to create a single template for aone these terms i.e single-theatre.php which works perfectly.

add_filter('single_template', 'single_template_terms');
function single_template_terms($template) {
    foreach( (array) wp_get_object_terms(get_the_ID(), get_taxonomies(array('public' => true, '_builtin' => false))) as $term ) {
        if ( file_exists(TEMPLATEPATH . "/single-{$term->slug}.php") )
            return TEMPLATEPATH . "/single-{$term->slug}.php";
    }
    return $template;
}

Within that template im using the usual pagination

<nav class="next-prev-links">
		<p><?php previous_post_link('%link', '<span>&laquo; Previous:</span> %title', FALSE); ?></p>
		<p><?php next_post_link('%link', '<span>Next: &raquo;</span> %title', FALSE); ?></p>
		</nav>

This works, however it doesnt limit to just the theatre term, once the lat theatre post has been reached it moves on to the next term.
Is there anyway i can get the pagination just to limit to its specific term.

Hope tha makes sense, Many many thanks in advance