Sometimes when I receive a phone call, the call connects, but then no sounds comes through, and I don't think my voice is transmitting either. When I try to call back directly afterwards, the same thing happens. However, once I've restarted my iPhone, it goes back to normal. I can't pinpoint what causes this to happen. Can anyone help me with this? I'm posting here because my phone is jailbroken, and it may have something to do with one of the many cydia apps I have installed.