cat_is_ancestor_of quit working in custom template

Hello,

I’ve been using a custom template (via custom functions) for a couple of years that displays certain category names/links in a post if those categories are checked. It suddenly quit working, and I don’t know why (I did just upgrade to WP 3.6 last week).

You can see the custom template here (it’s the Hike At A Glance Box at the top).

In my custom_functions file (the Thesis version of functions.php), I start off my custom template as follows:

/* ****START HIKE AT A GLANCE BOX BEFORE POST**** */
function hike_post_details() {
if (in_category('Hike Reviews')) { ?>

I use 2 instances of dynamically displayed categories. Everything else in this custom template displays correctly still (all fed via custom fields, with the exception of these 2 items that are fed via categories).

Best Season uses any season child categories (winter, spring, etc.) of the ancestor “hikes by season” category.

<?php
            foreach((get_the_category('orderby=ID&order=ASC')) as $childcat) {
            if (cat_is_ancestor_of(529, $childcat)) {
            echo $sep . '<a href="'.get_category_link($childcat->cat_ID).'">';
          echo $childcat->cat_name;
            echo '</a>';
                           $sep = ' ';
        }
        }
        ?>

And Difficulty uses any difficult child categories (easy, moderate, etc.) of the ancestor “hikes by difficulty” category.

<?php
            foreach((get_the_category('orderby=ID&order=ASC')) as $childcat) {
            if (cat_is_ancestor_of(114, $childcat)) {
            echo $sep . '<a href="'.get_category_link($childcat->cat_ID).'">';
          echo $childcat->cat_name;
            echo '</a>';
                           $sep = ' ';
        }
        }
        ?>

Despite having all of the necessary parent/child categories selected, these fields now appear blank on every single one of my posts.

Like I said, this has worked great for a couple of years, but suddenly quit working. The only change I have made in the last couple of weeks (when they last displayed fine) is upgrading to the most recent version of WordPress.

Any help is appreciated. Thank you!