This code is used when there are not products ...
Could you check the file:
/includes/templates/templates_default/templates/tpl_index_product_list.php
Do you see this code in it around lines 30 to 35:
Code:
<?php
// categories_description
if ($current_categories_description != '') {
?>
<div id="indexProductListCatDescription" class="content"><?php echo $current_categories_description; ?></div>
<?php } // categories_description ?>
This code is used when there are products ...
Could you look in this file around lines 58-63:
/includes/templates/templates_default/templates/tpl_index_categories.php
Code:
<?php
// categories_description
if ($current_categories_description != '') {
?>
<div id="categoryDescription" class="catDescContent"><?php echo 'MY DESCRIPTION: ' . $current_categories_description; ?></div>
<?php } // categories_description ?>
Now check your overrides for these two files ... is the code there? Is the code commented out?