Fixes for render AJAX HTMLRender objects

modules/product/classes/Model/Product.php

@@ -44,6 +44,13 @@ class Model_Product extends ORM_OSB {
 		'price_group',
 	);
 
+	/**
+	 * Which categories is this product available in
+	 */
+	public function categories() {
+		return $this->avail_category;
+	}
+
 	/**
 	 * Return the translated description for a category.
 	 */