Well, something very interesting happened. I put in 1 pound for product weight itself, then entered 0:10 for percentage:weight. On the Shopping Cart, the weight showed 1 pound. On the Shipping Estimator, the weight showed 1 pound. However, the available postage rates were such that I was shipping an 11-pound package. When I changed the percentage:weight to 0:1, the postage rates dropped like a stone. Does this mean that the Tare calculator is working, but you never see the results - anywhere?