yeah i get that they're an ancient magic but the way i see it is that a shout os a thu'um, a different magic that wards were not designed to stop, there fore they should still go through the ward.
It's the same thing to say that you can use a Ward to block the Shouts that the Draugr do on you, and also the Dragons, such as Yol (Fire Breath) ... it would make the game ALOT easier.
EDIT: You know right ? That when the Dragons breathe Fire or Ice on you, their are doing a Shout. So by your logic, you could use a ward to block the Dragon's shout and it'll make the game really easy and boring.