I am attempting to use a Plantronics HW261N headset with the OBI 1032 phone via the 3.5mm jack. This headset worked flawlessly with my old Polycom phone, but with the OBI 1032 I am hearing lots of buzzing and a very bad echo. I have played around with all of the Preference settings for echo, volume, and mic gain but none seem to have any affect. I have run out of things to try. Any help would be appreciated.