Netherlands Antilles (AN) is been dissolved since 10-10-10. The country does not exist anymore. It's now Curaçao (CW), St. Maarten (SX) and BES - Bonaire, St. Eustatius and Saba (BQ).
Please update your country database. An up-to-date ISO 3166 table can be found here. Its legend says for Netherlands Antilles:
Just as it takes a few months for ISO to update their tables with new/changed codes (ISO's update occurred on 12/15/2010), we need a few months to update our data based on ISO codes. We have made this change to our internal data and will update our public APIs shortly.