Tosh McCaber,
Flight Training has always required a Visa in order to enter the U.S. Since Sept. 11th, they are enforcing the requirement.
Hour building is not a training course. It is pleasure flying. With the current political climate in the U.S. it would be best to have a Visa for hour building, but it is not required. Without a Visa you could end up in front of an immigration officer that knows nothing about aviation, trying to explain the differences between training and hour building.
Good Luck,
Capt. Richard J. Gentil, Pres.
Naples Air Center, Inc.