I am having this problem also.
Right now, it just comes up saying there was an error. I have an USPS account & webtools are installed. I have been activated on their production server, & can reach it by sending an http request straight through in a browser so I know my account is ok. I looked through the code & am wondering why in the quote function in usps.php, $method is set to null as it is passed in & then the function does a check to see if the method is null. It is, so it does not perform _setService which then means it is passing on a null service. This seems to be the problem or maybe I'm just confused. In any case, it does not work.
Any suggestions would be greatly appreciated
Thanks,
M Newcomb
New 
