I have an odd issue with an ip phone (IPT2010SD). It registers fine and everything but when you call or pick up the phone you do not hear eachother. No matter if I call from my cell to it or it to my cell or to any other extensions. I am aware of the P2P Nat setting and have tried it both ways. It just starting doing this, it worked fine last week. Also what is very odd is I can reprogram the phone to a different station and it works fine. But when I even create a brand new station it does the same thing, I can't hear or be heard. What am I missing?