on the checkout page, you have code to set a static CouponCode session based on the coupon code form element:
<?php
@session_start();
if((((isset($_POST["txtPromoCode"]))?$_POST["txtPromoCode"]:"") != "")) {
$_SESSION["PromoCode"] = "".((isset($_POST["txtPromoCode"]))?$_POST["txtPromoCode"]:"") ."";
}
?>
all of the discount rulers are set up for other sessions like CouponIsPercent, CouponProduct and such, but there is no code in place to set those sessions.
It looks like only the rules have been created but not the code to set the sessions that are used by the rules.