bug

[sirchester]

My phone froze, screen faded to black then restated.

[_alexdon_]

Are you using battery savers or task killers?

[sirchester]

I am using app cache cleaner.

[_alexdon_]

Boot your phone in safe mode,see if that occurs anymore:

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008