Ahhh Bernie funny you should post this, I'm dealing with the exact same issue only with a 6x and 9212L's...register fine no audio either way, all setup seem's to be fine. I have (4) remote stations we are trying to setup and can't get a single one to work right...not even one from our office ( we did get it to work once but call drops every time after 16 sec's) huh?
I'm starting to suspect Charter's cable modem and blocked ports in that...routers are set at both ends correctly "we think" ! So going to give ISP a call today and see what happens...I'll let you know what we find.

...bob...

Bob Wells
WellComm, Inc.

"As long as nobody's dead or in jail, it can't be all that bad ! "