I have had the same problem and the software updates do not make a difference at all. I have tried contacting Sony Ericsson but they are not easy to deal with. I have had nothing but problems with this handset and would recommend you try to get rid o...
I have had the same issue and my phone has been in for the "software" updates which haven't helped. The Vivaz Pro is just defective! Sorry I know this doesn't help but at least you know that you are not alone in dealing with the Vivaz Pro problems.