NEWB to iPhone and this forum. Purchased a 3G through ebay. Seller claimed is unlocked but with TMobile sim it will not work. How can I verify it's been unlocked? When I connect to iTunes it states need to be updated but when I try to update it does not recognize the Tmobile SIM and will not proceed. Should I even try to update. Currently is 2.2.1. Any help is appreciated. I'm not a moron, but not a computer wiz either. A nudge to a good tutorial is much appreciated. Thank you in advance.