I experience somewhat similar issue. Sometimes when on a call (regardless whether it was incoming or outgoing) caller on the other end stops hearing me. The call is not dropped, I can still hear them well as if nothing happened, but they can not hear me. After that, the only cure is to cycle the power on the Obi box. If I simply hang up and try to re-dial it says that there is no service available.
This happens very often to me. Average talk time to get this failure is only about 5-10 minutes.
My setup is Obi100 with GV and Sprint.
