Share your experience!
Are you using some antivirus?
Boot in safe mode,see if the same occurs:
http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008
Have you tried a software repair until now?It might help.You can also stop by a sony service.
Same issue here, already tried factory reset but it still happen
Build number is 17.1.A.2.69