Has anyone had sucess with using QC 35 II in open office setting? I had had my QC 35 II for few days now and can not seem to get settings correct. Sound on my side is great, however, due to the mic sensitivity it appears the feedback is intolerable to anyone else on the line. Only solution is to constantly, mute but does not solve issue when I need to run the call or speak. If I can not get this resolved then I fear my only option is to return them and go back to Plantronics.