Support Starting Navigator kills internet connection

I've had my new Xperia Ray a few days. I bought it sim-free and it's on Vodafone UK. It is running 4.0.2.A.0.62. All is fine until I try to use Navigator or Maps or any app that uses the GPS. When I do, the GPS icon appears, and after a few seconds the 3G icon disappears. It never comes back, even when I exit the app, and the internet connection really is gone. If I go to the home page, disable mobile data and re-enable it, the 3G icon and the connection come back, and all is well again until I try to use one of the GPS apps. This is 100% repeatable.



Does anyone have any ideas? Does this sound like a handset fault?


Thanks,



--JSYN