s:TitleWindow didn't get focus when user click on moveArea until one of its children get the focus

Steps to reproduce:
1. Create a TitleWindow in a PopUp.
2. Attach a listener for the FOCUS_IN event on the titleWindow instance.
3. Click on the move area (an eventually move the TitleWindow around)

Actual Results:
The listener is not called.

Expected Results:
The listener should be called.

Workaround (if any):
Set the focus on one of the TitleWindow children, after that when the TitleWindow lose the focus, clicking on the moveArea is enough to get the focus on the TitleWindow.

You can find in attachment a dummy App to demonstrate the bug, uncomment the line 66 workaround the issue (but adding an invisible button only for that purpose looks a bad idea