I have a iphone 3G 2.2.1 with baseband 2:30. It is locked with AIRTEL india. I am using a airtel sim card and the signal is very weak. The problem is not with the AIRTEL signal as i get full bars when i use this sim in any other mobile. When everybody gets till the thrid signal bar, my iphone stays in NO SERVICE. When other get 3, 4 and 5 bars, my iphone gets 1, 2 and 3 bars. In fact this thrid bar i have seen only twice. This is very annoying for me. In my house its always NO SERVICE only. I have tried all the things i ready in the forums like a full restore, scotch tape. full charge and the others mentioned, but no solution. I would be very happy if somebody could help me on this.