Same here, Dice with Buddies still sent audible notifications as did email when Do Not Disturb was turned on last night..
What's up with that?
Your answer is down here...
I use my iPhone as my bedside clock (clock app) while being plugged into a speaker/dock. I didn't realize that the phone has to to be in the "Locked" state or DND does not work. Phone was beeping all night....