--- uc_product/uc_product.module
+++ (current document)
@@ -403,12 +403,11 @@
  */
 function uc_product_forms($form_id, $args) {
   $forms = array();
-  if (substr($form_id, 0, 27) == 'uc_product_add_to_cart_form' || substr($form_id, 0, 26) == 'uc_catalog_buy_it_now_form') {
-    $product = $args[0];
-    if (in_array($product->type, array_keys(uc_product_node_info()))) {
-      $forms['uc_product_add_to_cart_form_'. $product->nid] = array('callback' => 'uc_product_add_to_cart_form');
-      $forms['uc_catalog_buy_it_now_form_'. $product->nid] = array('callback' => 'uc_catalog_buy_it_now_form');
-    }
+  $types = uc_product_type_names();
+  $product = $args[0];
+  if (isset($types[$product->type]) && $product->type != 'product_kit') {
+    $forms['uc_product_add_to_cart_form_'. $product->nid] = array('callback' => 'uc_product_add_to_cart_form');
+    $forms['uc_catalog_buy_it_now_form_'. $product->nid] = array('callback' => 'uc_catalog_buy_it_now_form');
   }
   return $forms;
 }