No 'green light' from the USPS module

[Matt Noiseux]

We've installed the module, set up an account with USPS, entered our user ID in the module, the module is set to 'true', and the server choice is set to 'Production'. By all accounts we should be able to retrieve shipping quotes from USPS. But the USPS module is still with a 'yellow light' and we get no shipping quotes - not even an error message. We are using ZenCart v. 1.3.6.

Does anyone have any idea what might be the culprit?

[Ajeh]

You set your 5 digit US Zip Code?

You have installed the current version of USPS based on the May upgrade?
http://www.zen-cart.com/forum/showthread.php?t=97461