Produces checkout failure, BUT not locally!
More backstory. When I tried to select checkout wizard (with cart.php open), all selections were grayed. The problem I had yesterday was that in filling out the Payment tab, it selected an old connection setup and a dialog box kept coming up cyclically, trying to test the connection. So I re-ran the dynamic connection interface and added the correct live connection as an "additional" connection.
BUT, just tried the store locally, and it works. Where do I alter the connection so that it works online? THANKS!