I take it back. I'm still having trouble with mine too. When I reinstalled I just hit an address for testing and go to the first page without generating the error. All of my address data and the recipient's data showed up in the correct boxes. But I didn't go past the first page. When I do try to go on, I just get a page that says "Error" in the upper left corner in an otherwise blank page. (not the most informative error message I've ever seen). So I'm not resolved either.

I suspect that USPS has made some changes to their software. I hope the author of the module is able to fix it. I've really come to rely on it.