I have owned my Z10 since day one, and have had little to no issues with it randomly shutting off up until this week, it has turned off and restarted about three times this week. It will have about 60-80% battery and shut off, I was wondering if this has happened to anyone else? what is causing it? Please note I don't restart my phone often (usually about once to three times a month just to clear the RAM). Thank you for your help!