Product-kit update problem

Hi everyone,

I'm new to drupal (using drupal 7), and I'm currently using ubercart to create a product catalog.
I have recently encounter problem while creating/updating the product kit.
Whenever I add more than 5 items in a product kit or attempt to update an existing product kit, there will be an error. The error message is posted below. It seems to be something to do with "discount" function? I don't need the discount function as I am only developing a product catalog without any price/quantity field.

Notice: Undefined index: 118 in uc_product_kit_update() (line 244 of C:\xampp\htdocs\PKG\modules\ubercart\uc_product_kit\uc_product_kit.module).
Notice: Undefined index: 118 in uc_product_kit_update() (line 247 of C:\xampp\htdocs\PKG\modules\ubercart\uc_product_kit\uc_product_kit.module).
Notice: Undefined index: ordering in uc_product_kit_update() (line 275 of C:\xampp\htdocs\PKG\modules\ubercart\uc_product_kit\uc_product_kit.module).
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'discount' cannot be null: INSERT INTO {uc_product_kits} (vid, nid, product_id, mutable, qty, discount, ordering, synchronized) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => 115 [:db_insert_placeholder_1] => 115 [:db_insert_placeholder_2] => 118 [:db_insert_placeholder_3] => 1 [:db_insert_placeholder_4] => 1 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => [:db_insert_placeholder_7] => 1 ) in uc_product_kit_update() (line 278 of C:\xampp\htdocs\PKG\modules\ubercart\uc_product_kit\uc_product_kit.module).