I got a iphone 3g recently, I am forced to disable 3g to be able to send message and call even though my service provider told me they got the whole region covered :S
I heard of those problems before. And besides, honestly, I never really liked iphones. Because Apple has no history in making mobile phones .. That's the reason they were selling the 3G so cheap ... to attract more people to buy and increase their fame. I guess that failed ..