I dont' know if there is any pattern or not. It seems like the phone part of the phone (yeah that's right people a smart phone is supposed to have a phone that works too)... will lock up at random times. One pattern I noticed is that when I am calling someone, and if they don't answer, and then the next incoming call will be dead. I can answer, but its like a dead line. Othere situations are similar, like if I miss a call, and try to return the call, sometimes its dead. Each time I have to power cycle the phone. HUGE problem Are other people having this issue? any fix?