Have you tried using the APC-42 EHS? Must better setup:http://headsetplus.com/product1661/product_info.html 

Hi Mike,Here are some more information on compatible headsets for Cisco IP Communicator:http://headsetplus.com/faqdesk103/faqdesk_info.html

You can also find all the compatible SPAxxx compatible headsets here:http://headsetplus.com/category99_108/index.html

There are many Cisco 7900 compatible wireless headsets from Plantronics and Jabra, All the information you need is here:http://headsetplus.com/category99_105/index.htmlI'd recommend the Plantronics CS540, W740, Jabra 9450, or Jabra 920.  Just to name...