No Service

I just bought an iphone 4, factory unlocked from apple, cost a fortune, I am constanly losing signals, i keep getting "no service", I thought they fixed this issue, what do I do?, my old iphone 2g, has no problems, strong signal still. anyone else has this problem.

Is it the same problem thye had with the antena thing and you had to buy a rubber bumper, it comes back after a minute, but for what this baby cost, i should be sailing through all this stuff. Apple probably never fixed it.

I dont know what other problems exist yet, only had it 24 hours and already lost service over 24 times...