The 3.mm socket on the Droid Bionic is in a place where the case is curved, and part of the jack is exposed when plugged in. I thought this was the problem when I plugged in two different headsets and was unable to operate the phone properly. The volume controls and the voice control doesn't work.
But perhaps it is a pinout or other compatibility issue - I found many different pinouts at pinout.ru, also some mention of what's supposed to happen when buttons are pressed (changing impedance etc.) I don't think manufacturers do a good job on compatibility - neither the phone or the headset. My best headset is supposed to be iPhone compatible, and also compatible with MP3 players. Some places state compatibility with Droid, or now Droid Bionic.
Some discussion on Droid forums describes issues with the phone - intermittent or just not working with a headset. This was for the Droid (which I had previously and also had trouble with), and it doesn't seem like it has been fixed with the Bionic.
So, what's the story? Is there a headset that works? Or an adapter? Or a SW fix? Or should I return the Bionic?