Layout crashes out if Session dock is autohidden

What steps will reproduce the problem?
1. unpin the session panel so it autohides
2. in the menu click View -> Layouts
3. exception error will occur
4. select the same menu again and the Layout now appears in bottom dock view

What is the expected output? What do you see instead?
not an error at least.

What version of the product are you using? On what operating system?
1.2.0.11 (svn)

Please provide any additional information below.
Seems to only do it the first time, possibly due to it changing the Layout from 
being attached to the right side dock with the sessions.

        public void ShowWindow(DockPane pane, DockAlignment dockAlign, double proportion)
        {
            if (this.Instance == null )
            {
                Initialize();
                this.Instance.Show(pane, dockAlign, proportion); // <--- errors here due to pane.DocState being one of the autohides states.
                SuperPuTTY.ReportStatus("Showing " + this.Name);
            }

Original issue reported on code.google.com by djtrem...@gmail.com on 11 Jun 2012 at 2:14

Azaret / superputty

Layout crashes out if Session dock is autohidden #136