Yep, there must be something else I am missing. There are almost always 2 I/C paths open on the set even when they are on the phone because there are 3 I/C buttons programmed for each set. Just to be 100% clear I did verify with each test that no other I/C path was in use save for the incoming call. I will put a fresh set of eyes on it tomorrow but as of right now I don't see it.