As suggested by developer i reinstall the app (not any change) Then some day after the update come and i update the app then after my phone only ringing when call, no display wake even i unlock the phone still not shown any thing, the call show in notification bar only, then i click Green button, sometime call may pickup possible, sometime not, then i click profile button, after that my phone shown incoming call full screen and finally i can pickup call. WoW that's new process to take a call.