My Xperia E1 Dual is just 2 months old and restarts frequently and automatically. I have updated the phone software to latest available (Build No. 20.0.B.0.84). Although problem persists and update could not solve the problem.
I suggest that you try to repair the phone software using PC Companion..
Before repairing your device you may want to backup your information first. Check out this topic for more information on how to. How to backup?
If the issue should still remain I think that this needs to be examined and fixed at a repair center. For more information about how to submit your phone for repair and where, contact your local support team.
