AvalonDock DockingManager does not load layout

To save and load my layout, I followed the instructions here , but this did not work for me.

I have XAMLinside MainWindow:

<StackPanel Orientation="Vertical">
    <Button Content="Save"
            Click="SaveButton_Click"/>
    <Button Content="Load"
            Click="LoadButton_Click"/>
    <ad:DockingManager x:Name="myDM">
        <ad:LayoutRoot>
            <ad:LayoutPanel>
                <ad:LayoutDocumentPane>
                    <ad:LayoutDocument Title="Document">
                        <TextBox />
                    </ad:LayoutDocument>
                </ad:LayoutDocumentPane>
            </ad:LayoutPanel>
            <ad:LayoutRoot.LeftSide>
                <ad:LayoutAnchorSide>
                    <ad:LayoutAnchorGroup>
                        <ad:LayoutAnchorable Title="Left">
                            <TextBox/>
                        </ad:LayoutAnchorable>
                    </ad:LayoutAnchorGroup>
                </ad:LayoutAnchorSide>
            </ad:LayoutRoot.LeftSide>
        </ad:LayoutRoot>
    </ad:DockingManager>
</StackPanel>

And these are event handlers for clicking buttons:

private void SaveButton_Click(object sender, RoutedEventArgs e)
{
    XmlLayoutSerializer layoutSerializer = new XmlLayoutSerializer(myDM);
    using (var writer = new StreamWriter("test"))
    {
        layoutSerializer.Serialize(writer);
    }
}

private void LoadButton_Click(object sender, RoutedEventArgs e)
{
    XmlLayoutSerializer layoutSerializer = new XmlLayoutSerializer(myDM);
    using (var reader = new StreamReader("test"))
    {
        layoutSerializer.Deserialize(reader);
    }
}

After the window is shown, and I click the "Save" button, the file is "test":

<?xml version="1.0" encoding="utf-8"?>
<LayoutRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <RootPanel Orientation="Horizontal">
    <LayoutDocumentPane>
      <LayoutDocument Title="Document" IsSelected="True" IsLastFocusedDocument="True" LastActivationTimeStamp="04/12/2013 14:50:38" />
    </LayoutDocumentPane>
  </RootPanel>
  <TopSide />
  <RightSide />
  <LeftSide>
    <LayoutAnchorGroup>
      <LayoutAnchorable AutoHideMinWidth="100" AutoHideMinHeight="100" Title="Left" />
    </LayoutAnchorGroup>
  </LeftSide>
  <BottomSide />
  <FloatingWindows />
  <Hidden />
</LayoutRoot>

That's the problem: after clicking the download button, the document and the anchor disappear, and all I see in the window are two buttons and an empty rectangle where my layout should be. At this point, when I click the "Save" button, this is what is written in the "test" file:

<?xml version="1.0" encoding="utf-8"?>
<LayoutRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <RootPanel Orientation="Horizontal">
    <LayoutDocumentPane />
  </RootPanel>
  <TopSide />
  <RightSide />
  <LeftSide>
    <LayoutAnchorGroup Id="d3710e74-e6b5-4541-8b6f-554197c29dd6" />
  </LeftSide>
  <BottomSide />
  <FloatingWindows />
  <Hidden>
    <LayoutAnchorable AutoHideMinWidth="100" AutoHideMinHeight="100" Title="Left" IsSelected="True" LastActivationTimeStamp="04/12/2013 14:53:56" PreviousContainerId="d3710e74-e6b5-4541-8b6f-554197c29dd6" PreviousContainerIndex="0" />
  </Hidden>
</LayoutRoot>

I am using AvalonDock 2.0.1746.0. Does anyone know how to fix this?