Brand new iphone 4s, up to date\, had it for 1 week. It suddenly started lagging and when I tried to enter my passcode the keys dont work, I have to tap a number multiple times for it to enter but no matter how hard I try the pass code is never correct. In the background I can just barely hear the voice thing talking. Also, the slide bar hardly responds, in general it is lagging. There are odd highlighed boxes around my keys and slidebar. Have tried mupltiple resests, plugged into PC, nothing works???