If right mouse button is pressed while dragging a float tool window, the default context menu appears. If after that move away and do not select a menu item, the tool window cannot be released from the pointer and hence cannot dock or leave it floating.

ADD. RadDock - functionality to change the text orientation of the AutoHideTab
Comment: The text of AutoHideTab can be flipped for achieving of these requirements as the following code snippet demonstrates:
private void radDock1_TransactionCommitted(object sender, RadDockTransactionEventArgs e)
{
if (e.Transaction is AutoHideTransaction)
{
foreach (DockWindow window in e.Transaction.AssociatedWindows)
{
window.AutoHideTab.FlipText = true;
window.AutoHideTab.TextAlignment = ContentAlignment.MiddleCenter;
}
}
}

Currently it is not possible to customize the tool window animation and there is no animation when closing the tool window.

Resolution: 
Set the AutoHideAnimation and the AutoHideAnimationDuration properties of RadDock 

The ShowAutoHidePopup method should enable showing auto hidden pop-ups.

Tooltip text inconsistency between the dock's buttons.After hovering contiguously two neighbour buttons, their tooltip text is swapped.

RadDock tool tabs look incorrect with ControlDefault theme when RightToLeft layout is used.

The order of tabs in not correct after RadDock save/load operation. The selected tab is always the last one.

RadDock's ToolWindow should not hide when a modal dialog is shown while working with the window.
Solution: Added AutoHideWindowHiding event to RadDock to allow cancelling of the auto-hide windows hiding.

A nice addition to the existing save/load layout functionality of RadDock will be the possibility to save the AutoHideSize value.

The AutoHide popup is not shown in the scenario, demonstrated in the attached to the forum thread project.

FIX. RadDock - double clicking the expand tool window button causes the default form to redraw over the RadForm

There is a memory leak in RadDock when closing a document window with the context menu.

Add functionality in the Advanced Layout Designer to delete ToolWindows

A nice addition to the existing RadDock implementation for re-docking floating windows will be the ability to re-dock floating windows to documents if the previous state of the floating window was a document window.

In very specific cases, if one resizes RadDock, its content is not resized/redrawn correctly.

When saving the layout RadDock saves the windows as they appear in the DockWindows collection. However, improvement to save the current toolwindows position will be great addition.

Trying to Double-Click ToolWindow to dock it back on RadDock as a Tab...

When you set a ToolWindow to only AllowedDockStates of Floating,TabbedDocument and Hidden, you lose the header double-click functionality of the toolwindow that pops the ToolWindow out as a floating window as well as pops it back in as a tabbed document. If you add AllowedDockState of Docked, the double-click functionality works. 

I am working with ToolWindows on a RadDock control and want them only represented as either Floating or TabbedDocuments with the ability to double-click a floating window caption and pop it back onto the RadDock control as a TabbedDocument. I got the double-click functionality to pop a floating window back in by using DockStateChanged and TransactionCommitment events. The less important one of double-clicking on a TabbedDocument header to pop it back out I have not yet done.

I use the DockStateChanged event to fire when ToolWindows are set to floating and change the AllowedDockState of that window to use Docked. I use TransactionCommitment to change a ToolWindow's AllowedDockState to exclude Docked and programmatically change the DockState of the window to TabbedDocument. Is this the best approach or did I miss a simple property or something? I pasted the two methods below for your convenience.

Resolution: 

In Q1 2014 (version 2014.1.226) we introduced an floating option for tabbed document which resolved this issue. 
Here is the link to the feedback item: http://feedback.telerik.com/Project/154/Feedback/Details/111942-improve-give-floating-option-for-tabbed-document

To reproduce, just hover the over the tool window, open the datetime picker and press forward, backward or any other buttons on the calendar popup and you will see the tool window closing...

I'm hoping for a property to disable the closing of the toolwindow temporarily, or something that would suspend the close action...

FIX. RadDock does not load the ActiveWindow correctly.

FIX. RadDock SplitterWidth property is not taken into consideration, nor setting the MinSize of each splitter individually.