inbdz

Hi guys,
I have a problem in xperia arc s, it stops alone, I mean it stops suddenly, mainly overnight, specially if the wireless was on, I have doubt that connection programs affect this, specially viber and tango,becuse this problem starts after I install them every time, I fed up from formatting every time, please anybody has experience which kind of programs can cause this type of defection? small note about stopping.... if some one would call me he will hear the ringing tone but me I will not even realize this, I am forced to remove the battery to restart the smart phone