MPB toured SA in September of 2005
http://www.metalunderground.com/bands/details.cfm?bandid=375&tab;=news&page;=2

Before them the only international 'metal' (used here as a broad umbrella term) band to tour SA was Sepultura in September of 2003
http://sepultura.uol.com.br/v6/en/tour_dates.php

I think this still makes MPB the first hardcore band to tour SA