I'm losing my hair with this! I have set the Package Tare weight to Zero, I'd even checked the MySQL table and confirm it is indeed zero, but when I tested check out, it still adds a small quantity of weight to the total order.
I'm using the zones modules, originally I had the following setting:
3:25,6:35,9:45
When I purchased 1 item (all items were set to weight of 1), the shipping fee showed $25, which is correct. But as I increased the items to 3, the shipping fee jumped up to $35.
After much testing, I realized if I changed the setting to:
3.3:25,6.6:35,9.9:45
only it would show $25 for 3 items, and so on.
What I can gather here, for every item I put into the cart, 0.1 will be added to it. The question is: where did the 0.1 come from?!