To this point it's only been a single product (I shudder to think what will happen if there are multiple products). What's happening is that a flat-rate envelope is always being chosen, rather than a box of appropriate size. E.g., you can't ship a 6x6x6 4-pound product in a flat-rate envelope! The response from USPS in the Request Logs is: <?xml version="1.0" encoding="UTF-8"?> <Error><Number>-2147221202</Number><Source>Common:XmlParse</Source><Description>The element 'Package' has invalid child element 'Container'. List of possible elements expected: 'Width, Length, Height, Girth, Value, AmountToCollect, SpecialServices, Content, GroundOnly, SortBy, Machinable, ReturnLocations, ReturnServiceInfo, DropOffTime, ShipDate, RatePriceType, RatePaymentType'.</Description><HelpFile/><HelpContext/></Error>
So I'm presuming what needs to happen is the product dimensions need to be sent to get the correct box size?
P.S. I've been reading this forum for some time without having joined until now. The one thing I've noticed repeatedly is how quickly and insightfully you respond to user's concerns, so I just want to mention "WELL DONE!"