3G SIM compatibility with 3GS
Hey guys, I need your help.
I have a one-year-old 3G, still under contract. My buddy bought a 3GS for himself and one for his wife. The plan was to give her my 3G and I'd pay the $200 for her 3GS.
My SIM works flawlessly in her 3GS. Problem is, her SIM does NOT work in my old 3G... gives a "No SIM installed" error. My buddy's 3GS SIM also does not work in my 3G. I have no reason to believe that there is anything wrong with my old 3G; it worked fine before the swap. Also, her 3GS SIM works fine in a non-iPhone GSM phone (Motorola or something).