problem with installing ?price-break-1.11.2?and ?Gift Add (dangling carrot) v2.a?

[tomliuwhite]

I have installed one contribution named ?price-break-1.11.2_1?. Then I want to install another contribution named ?Gift_Add_V2.a?. But I could not. The problem happens in this page: catalog/includes/classes/shopping_cart.php

For the below codes:

$products_query = tep_db_query("select p.products_id, pd.products_name, p.products_model, p.products_image, p.products_price, p.products_weight, p.products_tax_class_id from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd where p.products_id = '" . (int)$products_id . "' and pd.products_id = p.products_id and pd.language_id = '" . (int)$languages_id . "'");

Both of these two contributions want to change it in their own way. I could not figure out. What shall I do? Many thanks in advance.