BNET - Log out Issue Mid-Game

Why does BNET keep kicking me off while I am in the middle of an online game. This was never a problem with the old bnet. This new bnet will freeze all of a sudden, and then log me out completely forcing me to log back into Battlenet from the desktop!! Why does it keep doing this to me. I am so tired of it. Some nights it does not do it, but other nights, if it happens once, it will keep on doing it. I think Blizzard gave my product key to someone else. Why else would it be logging me out?