Alphabetizing Posts in Category Pages – Multiple Categories

Hi! I am using the Genesis Framework and I am trying to alphabetize posts in Category Pages. My code worked well if the posts are classified only in one (1) category but once I try to classify one post into 2 or more categories, the code no longer works.

Here’s the code in my category.php template:

<?php

remove_action('genesis_loop', 'genesis_do_loop');
add_action('genesis_loop', 'category_custom_loop');
function category_custom_loop() {

    global $paged;
	$cat = get_the_category();
	$cat = $cat[0];
    $args = array('category__in' => $cat->cat_ID, 'paged' => $paged, 'orderby' => 'title', 'order' => ASC);
    $query_args = wp_parse_args($args);
    genesis_custom_loop( $query_args );

}

genesis();

Appreciate your help. Thanks.