I bought a new Sony Ericsson Vivaz handset from someone on eBay 2 weeks ago. I was told the handset was a free upgrade and the owner didn't like the use of a smartphone. Anyway, I bought the handset off from this owner. I discovered a problem on the 3rd day. I was trying to send some text messages on the handset, but as soon as I tapped 'send', the handset just restarted itself for no reason. The same thing happened 3 - 4 times in the same morning. Then on the same day I tried to call my brother from this handset. Once again, as soon as I tapped 'call', the handset restarted itself again. I was getting very annoyed with it. The problem went away next day for a few days and now it comes back again. I asked Sony Ericsson what to do and they suggested me to send the handset to them for examination, but it will take up to 10 days before the handset returns back to me. Why my Vivaz would keep restarting itself?? Help please!!!