Activate an AutoHide window from a floating document window

Hi,

I have an issue when the focus is in a floating  document window, if I call the Activate method of an auto-hide tool window, the tool window is not activated.

Here is the code to reproduce it:

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:docking="http://schemas.actiprosoftware.com/winfx/xaml/docking" x:Class="ActivationIssue.MainWindow"
        Title="MainWindow" Height="350" Width="525">

    <docking:DockSite CanDocumentWindowsRaft="True"
			UseHostedAutoHidePopups="False" UseHostedDockGuides="False" UseHostedRaftingWindows="False" IsLiveSplittingEnabled="False">
        <docking:SplitContainer>
            <docking:Workspace>
                <docking:TabbedMdiHost docking:Workspace.MdiTypeKey="{x:Type docking:TabbedMdiHost}">
                    <docking:TabbedMdiContainer>
                        <docking:DocumentWindow x:Name="DocumentWindow1" Title="My Document">
                            <Grid>
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="Auto" />
                                    <RowDefinition />
                                </Grid.RowDefinitions>
                                <TextBox />
                                <Button Grid.Row="1" Content="Activate ToolWindow" Click="ButtonBase_OnClick" />
                            </Grid>
                        </docking:DocumentWindow>
                    </docking:TabbedMdiContainer>
                </docking:TabbedMdiHost>
            </docking:Workspace>
            <docking:ToolWindowContainer RenderTransformOrigin="0.5,0.5">
                <docking:ToolWindow x:Name="ToolWindow1"  Title="Tool Window 1">
                    <TreeView x:Name="TreeView" />
                </docking:ToolWindow>
            </docking:ToolWindowContainer>
        </docking:SplitContainer>
    </docking:DockSite>

</Window>  

 code-behind:

using System.Windows;

namespace ActivationIssue
{
    public partial class MainWindow
    {
        public MainWindow()
        {
            InitializeComponent();
            DocumentWindow1.Float();
            ToolWindow1.AutoHide();
        }

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            ToolWindow1.Activate(true);
        }
    }
}

 Click on the button and... nothing happens !!

Sometimes even if you click on the ToolWindow tiotle bar, the tool window is not opened.

Best regards,