module suddenly not configured

[eliboone]

In the past week in our ferretdepot.com store we have had three US customers that had their orders shipped to PO boxes. Shipping could not be determined to these addresses. We are using Viking's USPS Domestic Shipping module. I just logged into Miva admin to check on the module and the mod is displaying the license agreement and wants me to enter the license key. This mod. has been installed and configured for over a year, but now it is suddenly not working. I have been having issues with a certain product being deleted from Miva. The store has been packing fine but I am wondering if there is some kind of corruption somewhere. Does anyone know of any reason why this would suddenly happen?

Thanks,