Help with Walker Class

Howdy. First time messing with the Walker Class, and I can’t get pst a problem. Documentation is found wanting for a newbie.

I have a custom post type. In it is a custom taxonomy. I want to change the output of wp_list_categories to get away from lists.

Here is my code on the page:

$post_terms=wp_get_post_terms( $post->ID, 'region');
foreach($post_terms as $q){
    $list_terms .= $q->term_id.', ';
}
$to_include = clc_shave_string($list_terms,2); (this just knocks the extra "," and whitespace off the string)
$args = array(
  'taxonomy'     => 'region',
  'orderby'      => 'name',
  'hierarchical' => 1,
    'include' => $to_include,
    'title_li' => '',
   'walker' => new My_Region_Walker(),
);
wp_list_categories( $args );

And my Walker:

class My_Region_Walker extends Walker {
    var $tree_type = 'category';
    var $db_fields = array ('parent' => 'parent', 'id' => 'term_id');
    function start_lvl( &$output, $depth = 0, $args = array() ) {
        $indent = str_repeat("<br />\t", $depth);
	}
    function end_lvl( &$output, $depth = 0, $args = array() ) {
	$indent = str_repeat("\t", $depth);
	$output .= "$indent<br />\n";
	}

    function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
	extract($args);

	$cat_name = esc_attr( $category->name );
	$cat_name = apply_filters( 'list_cats', $cat_name, $category );
	$link = '<a href="' . esc_url( get_term_link($category) ) . '" ';
	if ( $use_desc_for_title == 0 || empty($category->description) )
            $link .= 'title="' . esc_attr( sprintf(__( 'View all cruises filed under %s' ), $cat_name) ) . '"';
	else
            $link .= 'title="' . esc_attr( strip_tags( apply_filters( 'category_description', $category->description, $category ) ) ) . '"';
	$link .= '>';
	$link .= $cat_name . '</a>';

        if ( !empty($show_count) )
            $link .= ' (' . intval($category->count) . ')';

		/*if ( 'list' == $args['style'] ) {
			$output .= "\t<li";
			$class = 'cat-item cat-item-' . $category->term_id;
			if ( !empty($current_category) ) {
				$_current_category = get_term( $current_category, $category->taxonomy );
				if ( $category->term_id == $current_category )
					$class .=  ' current-cat';
				elseif ( $category->term_id == $_current_category->parent )
					$class .=  ' current-cat-parent';
			}
			$output .=  ' class="' . $class . '"';
			$output .= ">$link\n";
		} else {
			$output .= "\t$link<br />\n";
		}*/
        $output .= $link."\n";
    }

    function end_el( &$output, $page, $depth = 0, $args = array() ) {
    }
}

My problem is that the categories won’t line break after a parent with no child. Instead of:
Caribbean
Europe Mediterranean Greek Isles
North America Alaska
World
Asia Japan

I get:
Caribbean Europe Mediterranean Greek Isles
North America Alaska
World Asia Japan

Edited to add tags