Hey all... just wanted to post an update about a bug that has plagued us since the very beginning and may now finally be put to rest. We've had a few scattered reports over the years about users checking out without paying for shipping. A shipping method would actually be selected, but the shipping cost would come through as $0.
We just committed a fix that should finally solve this pesky problem. We try to avoid updating existing store versions whenever possible, but in this case we patched it back to version 0.3.0. Please let us know if you find anything out of the ordinary.
For the curious, the $0 shipping bug was caused when someone updated their address, selected a shipping method and then changed the address by selecting the "use a different address" or something similar and then checked out while the AJAX results were still loading. The old values hadn't been cleared out yet so the validation code thought everything was fine but no shipping method was selected a second time to update the price.