516187 Safari & iOS Browser (Variable) problem

We're running into a problem with a couple variables on our checkout page. The page has MANY variables, and all of them are working fine on IE, Chrome, and FF. In fact, ALL except two variables are working on Apple browsers. However, these two variables are not working properly on: * Safari 5.0.3 (6533.19.4) on Mac * iOS 4.2.1 (8C148) on iPad * Version 4.3.3 (8J2) on iPhone I've attached a screenshot of the problem, and the php file which generates this page. I should add that on one machine running Safari 5.0.3, the variables are also working fine. You'll note the two variables that aren't working are in relation to calculating the final price at checkout. I need to solve this as quickly as possible, as users on the "broken" versions cannot currently buy anything on our site since no value is being calculated to pass through the payment gateway. Please include the word APPLESAUCE as the first word of any reply or bid to ensure you've read the full post (and hopefully looked at the attachments).