I have the Verizon-model iPhone. My son and I have been enjoying Facetime, especially when I travel. I should say that *I* am the one joying it, because he never sees any video from my end. When we connect a call, I get decent video of him, but he sees only a freeze-frame of me. Sometimes he doesn't even get the one frame, and his screen stays black during the entire call. Is there anything we can do to troubleshoot and/or correct the problem?