Kevy, this thread is for the Quantity Discounts contribution, configured through Admin->Modules->Order total. It sounds like you're using the native Quantity Discounting in Zen Cart which is configured using Admin->Catalog->Products Price Manager.

You might try temporarily deleting your copy of includes/templates/YOUR TEMPLATE/tpl_product_info_display.php so that you're using the default one, to see if that fixes it; then you'll know the problem is in that file.