"No Shipping Options" ERROR!

Whenever a customer checks out on my website they receive this error:

[QUOTE]Unfortunately no shipping options are available for your location.

Please contact us and we will see about delivering to you.[/QUOTE]

This are my settings:

Shipping Methods

A) National USPS First Class Shipping

B) Inational USPS First Class Shipping


A) National

In National I have USA, Puerto Rico, Canada and Mexico

B) In International I have every other country.



USA as default. In the Items I have:

Countries: USA

Currencies: US Dollars

Languages: English

I think that pretty much explains my options. I pretty much just want to charge $3 shipping for USA, Puerto Rico, Canada and Mexico and $4 for everywhere else. It should be pretty simple. Please help!