Change your shop.product_details.php as follows (notice this is just before 'category navigation'):
//AK: allow for mambots
global $_MAMBOTS;
$_MAMBOTS->loadBotGroup( 'content' );
$row->text = $product_description;
$results = $_MAMBOTS->trigger( 'onPrepareContent', array( &$row, &$params, $page ), true );
$product_description = $row->text;
//AK<
/** Get the CATEGORY NAVIGATION **/
That same module works fine with me this way.