I have an iphone 3g running on firmware 3.1.2 (7D11) and modem firmware 04.26.08. The phone has been JB and unlocked to allow SIM card from Vodafone to be used. I have had the phone for just more than one year.

Ever since I have been using the phone I have had problems with reception. Once the call is made or received, the connection is breaks up after a short conversation. Looking at the display the reception indicator shows no service. Or switching between 3g and EDGE! The transmission in the area is perfect as the phone before the receiving the call shows minimum 3 bars.

This is particularly bad when I am traveling on a moving car or ever walking.

I have had the SIM card replaced 3 times by my provider. I have had the phone firmware updated and phone setup. Sometimes I reset all setting several times in one day. I have switched off the 3g to see if there is an improvement. All that with no success.

I have come to the conclusion that the problem is with the phone hardware rather than the firmware as my partnerís iphone (identical phone) works without any problem. We both have the same provider. I have also tried my SIM card in her phone and vice versa. The problem is still the same.

Has anyone experienced this problem? Does anyone know how to solve the problem?