Problems applying shipping costs across different items

Hi,

eCart5

I want to add a £2.95 shipping cost if the sum of all items in the shop is < £12 otherwise shipping is free.

I have set up the following calculation (see attachment)

(([Price]*[Quantity])<12)?(2.95):0

and a shipping rule (see attachment) 'ShippingLessThan12'

My shop at www.belindaclark.co.uk/shop.php shows the item layout - although this live view doesn't have the above rule applied yet - the page is populated from a MySQL database in a repeating group to make adding new products easy. (See attachment for test screenshot)

The problem is that if I choose the same item on the shop page the rule works, adds shipping until cost is £12 or greater the rule works fine, but if I choose different items it adds the shipping cost to each unique item so it appears it's not checking on the subtotal (excluding shipping) to date and just looking at individual item totals.

I've attached

Screenshots of the rules and a test screen with an incorrect total.
eCart_Definition.php
shop.php
comfirm.php

Thanks

Dave