Got my iPhone 4s yesterday, set everything up today, finally sat down with it this afternoon, spent about 2 hours playing around with a bunch of things, it was warm, from games, etc. But not hot or anything. Anyways, all of a sudden text entry became all messed up, the screen acted uncalibrated, turned it off and back on, worked alright outside of several dead spots, mostly along the right edge. The letter "o" on the keyboard for instance, or the backspace, totally unresponsive. Turned it off for about 30 mins and back on, now it seems fine. Anyone else experienced this? This is my FIRST iPhone, and this makes me feel very uncertain about Apple quality control.