Those posts were from people who had no clue -- I read them as well. They talked about OS4.5 on older devices. Their theory was that the carriers and RIM were in cahoots to keep clients on the original networks. That was a load of made-up crap. Your OS isn't frying your SIM. Your SIM may not be fried either. Try it on another phone, or reload the OS if you don't have one. You have nothing to lose. Is this by chance an unlocked phone? What carrier are you on? Anyway, I am sure it was not the OS that did your SIM in. It could also be an old SIM card that just died?