I'm another person now suddenly struggling with the AutoFill contribution and USPS error messages. I'm on ZC 1.3.7 and have never had any problems with the mod until Friday, 4/21. We've found that international (outside the US) labels will autofill just fine, but the domestic (US addresses) will not. Perhaps that's another clue as to what is going wrong? I've got hundreds of labels to print, so any solution will be *most* welcome!