The Country & State database was updated to include Sint Maarten (http://en.wikipedia.org/wiki/Sint_Maarten)
The issue was first reported in a post: http://forums.clickandpledge.com/sho...hlight=maarten
If you are using the Country & State database in Salesforce please synchronize the database to update your local copy. The country will appear in the list of countries in the Virtual Terminal.