Also i have same problem since begining of the july. First screen freeze accured when i opened my phone after 2 or 3 hours charging period. Screen freezed, one or half an hour after phone turned normal situation. After 5 or 6 days from first freezes screen has freezed again. i try out the all restart and reseting button combinatin, phone has restart after each try but screen has not responsive all touches and screen completly freezed. All buttons are working very well, i can take a photo but the screen dosent working.
At last i sent the phone to service last friday i have still waiting what is the problem and wonder what is the source of problem