I bought the iphone used and it was unlocked. I accidentally updated it to 3.1.3 after the phone crashed. Now it is locked at the emergency screen. It says Fido, Rogers, Telus, and AT&T SIM cards are all not valid (yes i have access to all of them to try). Now i understand that at this point it can't be unlocked. But how can i get it to work with Fido if it was originally locked with Fido? Any way to find out what it is locked to?