I only read the first post a few minutes ago, and also think its to do with the international setting. There is also some further information here and links back to this forum: http://iphone.fiveforty.net/wiki/index.php/Main_Page

Motaz..
Ana Ali i called few days ago
look i want to see u with the phone and we might figure out whats wrong b4 u sell it or even go to apple stores.. just give me a call..u know my # if u need it send me again