ScriptUI "palette" window doesn't close in PS CC 2015 / Mac OS

I have a simple extension made in Eclipse Extension Builder with buttons that call jsx scripts. In my scripts I use "palette" type windows like this:

var w = new Window("palette", "Tittle");

// ScriptUI elements I need here

var closeButton = w.add("button", undefined, "Close");

// just to prevent window from fading out

w.onDeactivate = function(){

   w.update();

   };

// keep palette opened until user click button or close window

var closeWin = false;

closeButton.onClick = function(){

   closeWin = true;

   w.close();

    };

w.onClose = function(){

   closeWin = true;

    };

w.show();

while(closeWin == false){

   app.refresh();

    };

This works well except in PS CC 2015 on Mac OS, where users report that the windows cannot be closed at all or reappers after user switch between ps documents or apps. Only way to get rid of the dialogs is to close the extension.

Do you have any idea how could I fix the problem / what it causes?

Thanks a lot,

Patrik