this ios looking for an item in your cart with the ID of 0 If an item with the ID of 0 is not in the cart, the rule will not trigger.
also, the calculation Item 0's FlatRateShipping plus 0 is retuning the FlatRateShipping for the item with the ID of 0.
Okay maybe I misunderstood. The rate is going to be different for different items in the catalog based upon their size. I have that info in the database. Is there a way to make this shipping look up dynamic data?