I can't really understand it but a friend of mine has an iPhone and it only picks up one of the two carriers of my country but it used to pick up both. The real problem is, it isn't picking up the right one, the one that is in the sim tray (Cable & Wireless). It doesn't make sense why it would all of a sudden do that.

Anybody else have had or even heard of this problem??????

Any help would be greatly appreciated.