Has anyone had this issue, it has happened to all 3 Hero's that Sprint has replaced, out of no where it goes into sleep mode, does not matter what button I hit it does not wake back up, I have to actually take the battery out and replace it and then turn the phone back on to get it back on. Is there something that is causing this issue if anyone else has had this happen, is there a solution to wake it up without having to take the battery out, it does not happen often, but at least once or twice a week.