I bought my iphone 3G in Amerika. It did work very well untill i was stupid enough to upgrade it to 2.0.2 end then my iphone could not find any signal(no service). Then I downgraded the iphone back to 2.0.1. as i bought it. And it still does not work,finding any signal. I also bought the chip(simcard) wich unlockes the iphone in when i was in Amerika. But it is not working. if there is someone who can help me with this problem, please help me ?