I have had my iPhone for a couple of days, but I didn't activate it until last night. I haven't been able to receive calls or SMS. I can make outgoing calls and SMS, but when someone else tries to call my iPhone they go straight to voicemail or I never receive the SMS. I have been using Wi-Fi so that doesn't block signals like EDGE does, correct? Any suggestions as to why I am not getting calls, voicemail, or SMS while I can make outgoing calls and SMS perfectly fine?