I have uploaded all the files that are stated and then enabled the "Royal Mail 1st Class "Packet"" shipping module. I have not changed any of the settings apart from setting "Enable this shipping option" to True.

I have then added a product with the weights of 0.1, when I add this item to the cart and estimate the delivery, to a UK county it is stating that the delivery cost will be £8.22, this can't be right. This price is also stated if I continue to the shipping section in the checkout.

What am I dong wrong?

I am using version 1.3.8 of Zen Cart.