hi guys. i have an issue here. just bought xpzu for a week and i've been hsing it for a week already. the problem is related with SOD & fake hang. but only happened if i want to make a call using phone dialer. the moment i pressed call, the screen just shows black screen. i cant even know how many minutes in call. luckily i set the power button to end call, otherwise i cant even touch screen. already updated to latest firmware .257, performed steps to prevent it from happen (force shutdown, set auto detect light) but still the same. any idea how to fix it? btw my other xperia z doesnt have such problem..