Using the iPhone 6 Plus, I've been noticing lately that the home button often doesn't take me to home, power button doesn't turn on the screen. I have to press them 2-3 times before it responds again. I thought I may be pressing it wrong, or didn't register the click, the next time it happened, I tried using different hand with a bit harder push, didn't work. This seems only to happen during/shortly after heavy (facebook, twitter, instagram, safari, all seem image heavy) use where the phone is warm/hot in the back. someone suggest to take it to apple store since it's still under warranty, but when it's not hot, the button seems to work okay. I wonder if anyone has experience this before.