I have a new installation of 7941 phones on CUCM 6.1. Customer is using some Plantronics Headsets (some existing, some new), but none seem to work unless they are plugged into the Handset port of the phone. They then work if the Headset button is pressed. If Headsets are plugged into the Handset port, the Handset does not work.
As far as I know, I don't have to configure anything on the CUCM to enable Headsets.
Has anyone seen this before, or is there something missing?