I have had the same problem no matter what I setup. I tried one flat free for USPS and I tried setting up box size carriers for USPS flat rate boxes and it seems to work at first, but after testing it for a little bit, it automatically says free shipping on everything. I can not have this. I have had a Ipage site since Aug. I have been paying for that I can not use because of this. Ipage won't help me because it is a Prestashop issues and Prestashop does not support their service which ipage endorses unless you buy a hundreds of dollars support package and go through more hassle. Why don't they have automatic shipping set up by box six or region? This is ridiculous, thinking it might be time to contact BBB, no one seems to help and lot of people keep reporting the same issue.. though Prestashop seems to say everything is fine. Well, then why does it work for two minutes and then suddenly will not, something glitchy there, I did everything as it shows. And don't even try adding extra shipping for two items in cart, that automatically screws up. I don't know how much time I spent setting up my web store to have this stupid shipping issue hold me up for month upon month upon... you think they would be nice and quickly set it up ? Is that so hard.. for someone who has been asking for some assistance, I know it don't take them any time. Any programmer or someone who has theirs working. I would really appreciate your help!!! Thank you!