Please help. I was getting estimates of both UPS and USPS shipping fine (plus free shipping for orders over $50.00). Now a day or two later I'm getting the error "sorry - not shipping to your region"

Using version 1.3.8a. Zones definition is Continental US. Shipping modules installed are UPS, USPS, and Free Options - BUT NONE OF THESE HAVE ZONE RESTRICTIONS set.

Please help!

Thanks!