I am guessing that Capone's name was technically pronounced Caponi as I believe Don Corleone's was as well. I think probably Americans pronounce it the exact way it was spelled and it just "stuck".
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK
