So i just got a black 16gb iPhone 3g. I sent a text to my Dad (AT&T), and Mom (T-Mobile), who both got it immediately. However, they both texted me back and i only got the one from my dad. I also asked my other friends to send me a text (they are on T-Mobile, and Verizon) and they did, but I never got it. Is there some setting i have to adjust, or some way i can fix this?