Steps to reproduce:

1. Open the form at design time
2. Add a RadDock
3. Add a MS Panel
4. Put the RadDock inside the panel
5. Dock the Panel to Fill, dock RadDock to Fill as well.
6. Open RadDock's Advanced Layout Designer
7. Add two ToolWindows to the left and redock them in order to share one common container.
8. Hide the ToolWindows by unchecking the check-boxes in the Advanced Layout Designer and save the changes
9. Add a RadPanel (Dock=Fill) to the active ToolWindow.
10. Add a RadGridView (Anchor = Top, Left, Right, Bottom ), a left RadButton (Anchor = Bottom, Left) and a right RadButton (Anchor = Bottom, Right)to the panel.
11. Save thfs in the designer. Select the RadPanel with the grid and the buttons and click Copy.
12. Select the other ToolWindow and paste.
13. Save the form. Close the designer and reopen it again. You will notice that the pasted panel is not as expected.

The attached video (drag and drop over the browser to play it) illustrates better the performed steps.

Workaround: do not place the RadDock inside a MS Panel. RadDock is supposed to be used as a main container in a form.