I have my Obi set up with Google Voice. It worked fine the first few days, then I ceased getting a dial tone when I picked up the phone. The key tones don't work either. I tried hooking more than one phone up to it, and still nothing. However, when I'm receiving a call, the phone will ring. When I pick it up, the phone stops ringing but the call isn't actually answered (my Google Voice cell phone continues to ring, and using it is the only way I can connect). Is the Obi just not detecting when the phone is off the hook? How can I fix that?