I have a Plantronics CS540 w/APV-63 on a 1416, it will not activate the headset button to answer or release, I replaced both the headset and EHS with no change, I then took it to another site and installed it on a 1408 and it works fine, site A is a IP Office running in basic mode w/8.1.85, site B is IPO Basic 8.1.67, does anyone know of a issue with .85 or do I have a corrupt SD card, any input would be greatly appreciated