title: pjsua_conf_disconnect do not mute mic on some Mac
body: <p><strong>The question:</strong></p>
  
  <p>Is it possible that under specific condition (hardware, ...) the <code>pjsua_conf_disconnect(0, callInfo.conf_slot)</code> function do not mute the mic?</p>
  
  <p>If yes, how can we effectively mute the mic with PJSIP?</p>
  
  <p><strong>The details:</strong></p>
  
  <p>In a OSX SIP application, user can mute the mic, and this will call:</p>
  
  <pre><code>...
  pjsua_call_info callInfo;
  pjsua_call_get_info([self identifier], &amp;callInfo);
  pj_status_t status = pjsua_conf_disconnect(0, callInfo.conf_slot);
  ...
  </code></pre>
  
  <p>Where <code>[self identifier]</code> is the <code>pjsua_call_id</code> of the current call.</p>
  
  <p>I know for sure that after those 3 lines, <code>status == PJ_SUCCESS</code>, because only if this condition is true the UI is updated to let the user know the mic is muted.</p>
  
  <p>This project uses the <code>pjlib 1.12.0 for POSIX</code> static libs.</p>
  
  <p>Users that face this problem are on Mac OSX 10.8.1 and 10.8.2. They are all using their built-in MacBook [Pro,Air] mic, no headset.</p>
  
  <p><em>Note that I am NOT able reproduce this problem myself on an OSX 10.8.2 mid-2009 MBP with the exact same build (from the MacAppStore), this is what making this problem hard to trouble shoot.</em></p>
  
  <p><em>Note that it is not a random problem, it is contant: as the mute function never works for users experiencing this issue, and it always work for the others.</em></p>