MEXICO CITY (AP) - Alarmed by Cuban President Fidel Castro's 's sudden departure from a U.N. summit last week, some Mexican lawmakers are demanding explanations from Foreign Secretary Jorge Castaneda. Castro suddenly left the U.N. development summit in the northern city of Monterrey on Thursday, citing "a special situation created by my participation in this summit." Later, the Cuban government accused Castaneda of bowing to pressure from the United States to prevent Castro from participating in summit events, an assertion both Castaneda and President Vicente Fox denied. The Cuban government on Tuesday called Castaneda the "diabolical and cynical architect" of...