Thanks for the reply Ajeh.
I have tried with the zone selected and that disabled the module, (the radio button on the admin>modules>shipping modules went to yellow from green when I selected the shipping zone).
I have not used USPS on the site, I just started setting up the site recently.
I have used the same USPS Web Tools User ID, on the module settings, that I use on two other non-zen-cart sites.
Is it possible that USPS does not have the account to the Production Server for this site I am setting up with zen-cart even though the same user ID is used on the other non-zen-cart sites?
Thank you again for your help.

Van