I've only had my Global 2 a month and seem to be having a recurring problem with the sliding lock. Sometimes I am using the phone playing games or another app and suddenly the screen goes black and I have to hit the power button to get it going again. When it opens the sliding lock has been engaged. It does this over and over until I do a hard boot (turn the damned thing completely off). That usually takes care of it but not always. What am I missing or doing wrong?