Edited Issue: Not able to unhide auto hidden part (LayoutAnchorable) [22267]

Hi guys.

I want to report one big problem which we have with the AvalonDock in Extended Wpf Toolkit version 2.8.0. Problem is that in some cases it is not possible to unhide auto hidden part (LayoutAnchorable ). I've attached the source code (visual studio 2015 solution). You can also download it here:
[https://dl.dropboxusercontent.com/u/46583507/ProblemWithAvalonDock.zip](https://dl.dropboxusercontent.com/u/46583507/ProblemWithAvalonDock.zip)

Here are the instruction how to simulate it:


1. Open the solution
2. Run the application (F5)
3. Set focus to the textbox Text1
4. Select Tab2
5. Select Tab1
6. Hide Part2 (Auto hide)
7. And now you will not be able to unhide the hidden part