I work 3rd shift and I was playing around with my phone (still learning it) and I accidently called a friend at 3 in the morning! I tried everything to get the phone not to ring but my screen went to black giving me no access to the dialpad and other buttons. I could not wake the phone up until after it had started ringing! I tried shaking the phone, pressed the power/lock button and the phone still rang and the screen was still black then finally on the 2nd or 3rd ring my screen came back and I was able to tap END!!!! I was like what the heck was that all about!