For the past month or so many people have been plagued with the Killstreaks not stacking glitch. For all of you who don't know what I am talking about its basically this: Say you have earned a Pred missile but you have not called it in yet. You earn another one but instead of having two, you only get one. I just got done talking with one of the dev's on the chat and support and they said that its a bug and they are working on fixing it. So no, it is not a part of the game and was not intended to be in it...... Now.... We wait.