Wrong answer, that isn't the fix, the fix is bringing it to a sprint repair shop. Either that or you haven't allowed your phone to completely activate, note that activation may take up to 24 hours. Im haveing this same very freaking annoying problem on my evo. Its a little fustrating buying a phone this expensive, having it for 3 months and then, boom dosent want to work. Anyways, I called and they said I would have to bring it in to a sprint repair store because apparently my phones software is all jacked up. The woman on the phone said its a 30 min fix and costs nothing to me, still, how this happened idk. She suggested that when my phone did a software update, it didn't install it correctly. Hope this helps everyone else.