Regionalize Events

Hello, I am traying to make the calendar only display events for a particular region, which is set in the session variable.

I created a template page which uses the calendar plug in.

I put this code at the top of the template page:

$region = $_SESSION['region'];

			global $wpdb;
			global $query_string;
			$term=get_term($region,'regions');
			$slug=$term->slug;
			$query_string.="&regions=$slug";
			query_posts($query_string);

The above works, but when I add the query_posts function (last line of code above), it affects the output and shows the_content as plain text list of events instead of the calendar. In other words, the output is overwritten by the query_posts plug in.

Any idea what I am doing wrong?

http://wordpress.org/extend/plugins/the-events-calendar/