
We use USPS as the shipping provider exclusively, and recently the USPS API started to feed us garbage. I was alerted by one of the customers and we believe it has been fixed at this point in time.
Our current policy is that what we charge for shipping is usually a little more than direct cost of the shipping, because packing materials have a cost. When filling orders and what has been charged for shipping is much greater than what it costs us to ship you will see a refund come back to bring that inline. Where possible we also will combine orders and refund shipping.