Unity 3.4.1 double click script in project panel no longer sync with MonoDevelop

After upgrade to Unity 3.4.1, double click a script can open MonoDevelop, but no longer open the right file. Do anyone else meet the issue?

Mac OS X - 10.6.8
Unity - 3.4.1f5
MonoDevelop - default version ship with Unity, 2.4.2 (12610f)

Turns out a OS restart fix it. Kind simple and stupid.