Question Problem at touch xperia u

HiI've changed my phone touch often comes a message or ringing phone, touch phone freeze that should bring his battery again and turn it this does not work restored 4.0.4 . the original ROM, now I have custom Flash ROM 01/04 Touch freeze is a little better but still no one knows where is the problem?
Also, with the touch-freeze Touch original same problem in my call.
sorry for my english