I had purchased Samsung x670 within 3 months of purchase is started getting problem that while talking that phone automatically hangs and restarts again. I had been to the service centre as it is in warranty. The kept the phone for many days and tried but they said that they are not getting that problem. And after going to them again and again the changed the motherboard but still the problem is the same. They said now they are helpless and they cannot do anything. I am fed up. As the phone costs 9000 bucks and it is not a small amount.