Using Cisco IP Communicator 220.127.116.11 with a Plantronics DSP 400 usb headset. Headset audio and mic test fine in cisco. When I receive a call, everything works fine. When I place a call, I hear audio but, the person I am speaking to cannot hear me. All device settings are configured properly and I have tried initiating a call using both the "headset" button and the "speaker" button. Using a Dell Inspiron 6000 laptop. Thanks for any help.