The phone and Plantronics Voyager 510s are connected with a APC-4 Headset Hook Switch Control Adapter. When I press the silver call connect button on the side of the headset, I can hear the headset base click and come off hook, but my phone does not come off hook any more. This setup was working perfectly, right up until recently. It seems to have stopped working right after I installed the most recent devpack on my cucm 5.1.3 nodes. Any ideas?