I have a couple of the Plantronics Savi w720 headsets and am wanting to pick up calls using the button on the headset. I have followed the instructions at http://www.3cx.com/support/plantronics-configuration/. Unfortunately I cannot set the default softphone. 3cxphoneforwindows simply isn't listed. I thought it might not have been required; however I have tested and I still cannot answer or end calls using the headset's button. Any assistance would be greatly appreciated.