I have this goofy problem with a new uc320w install
Its a simple setup, 6 phones, 3 pots lines (Verizon)
Sometimes during outgoing calls, while the customer is dialing the phone just goes back to the main menu like they werent even dialing
Sometimes it takes them several tries to complete a call.
There is no stutter tone on any of the lines I checked that.
oddly this problem seems to start when I discovered I had the upstream bandwidth limited to 128k and modified to 4m or so
(i dont see how its related though)