In the beginning of Part II, Senator Geary pronounces "Vito" wrong at Anthony's First Communion party. Later, at the senate hearing, he pronounces the name correctly. Just a small detail showing his newfound respect and loyalty to the family.
I always thought that his mispronunciation was done on purpose, to show his contempt for Michael and his disgust at having to make nice in public. He pronounces "Cor-lay-own-ay" just fine when he meets with Michael afterwards in private, insults Michael and makes his own rather greedy demands.
