This past week, my iPhone has been having some problems with incoming calls. When someone calls me, I slide to unlock to answer, and I notice that when I put my phone to my ear, the proximity sensor doesn't turn the screen off, and I can't hear the person on the other end, and they can't hear me. So far this has only happened when I'm on EDGE network, not 3G. Also, if the person tries to call again, the problem will happen a second time, but if they call back a third time, the proximity sensor works and I can now hear them (and vice versa). My phone is on the latest firmware and is jailbroken, but I haven't really changed anything in the past month or two, and the problem has only been happening for a week. I've also tried turning the phone and back off and doing a hard reset, and neither have helped. Any ideas?