I used to make phone calls and be able to change to speaker, mute, and whatever else. Just recently, whenever i pick up a call, the screen goes black and i cant do anything until the call has ended. God forbid their voicemail picks up or ill have to either wait till the message length limit is over or just simply power down the phone. Any clue why this is happening? I will bring up I also recently added quite a bit of music to my phone but i dont know how that would affect my phone in this such manner.