Mac Main Window demo bug - search field doesn't lose focus

[svalovic]

I am using a native search field in my mac application. It doesn't lose focus after clicking to other widgets that should react to keyboard inputs. My code is based on the code from an official demo:
http://qt-project.org/doc/qt-4.8/demos-macmainwindow.html

But it doesn't work in the official demo, too!

I have tried to set the first responder to other widgets after clicking on them, but that keeps crashing for me.
Does anybody know how to use the native mac search without these problems?

Thanks