Retaining anchors when placing a flow document via pagination

I am trying to create a simple reporting and printing system in WPF in .NET 4 and after countless hours trawling SO and various online tutorials I have the following (simplified) setup which should accept a streaming document containing a report template add the data source to as a datacontext, put it through pagination and get something display / printable.

The report is laid out in a streaming document in a separate content file (DefaultReport.xaml):

<FlowDocument xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Paragraph FontFamily="Arial">
        <Run Text="1"/>        
        <Run Text="{Binding Path=MyText}"/>
        <Run Text="3"/>        
    </Paragraph>
</FlowDocument>

      

        
        
        
      

    

Datacontext is a simple object:

private class MyDataContext {
    public string MyText { get; set; }
}

      

        
        
        
      

    

Loads and stacks like this:

using (var stream = File.OpenRead("DefaultReport.xaml")) {
    FlowDocument document = (FlowDocument)XamlReader.Load(stream);                
    document.DataContext = new MyDataContext { MyText = "2" };

    flowReader.Document = document;           

    XpsDocument xpsDoc = LoadAsXPS(((IDocumentPaginatorSource)document).DocumentPaginator);
    fixedReader.Document = xpsDoc.GetFixedDocumentSequence();
    xpsDoc.Close();
}

      

        
        
        
      

    

LoadAsXPS turns a flowdocument into an XpsDocument like this:

public XpsDocument LoadAsXPS(DocumentPaginator paginator) {
     MemoryStream stream = new MemoryStream();
     Package docPackage = Package.Open(stream, FileMode.Create, FileAccess.ReadWrite);

     Uri uri = new Uri(@"memorystream://myXps.xps");
     PackageStore.AddPackage(uri, docPackage);
     XpsDocument xpsDoc = new XpsDocument(docPackage);

     xpsDoc.Uri = uri;
     XpsDocument.CreateXpsDocumentWriter(xpsDoc).Write(paginator);

     return xpsDoc;
 }

      

        
        
        
      

    

flowReader and fixedReader output the results of the whole operation and are defined in xaml as

 <FlowDocumentReader Name="flowReader" />
 <DocumentViewer Margin="0,10,0,0" Name="fixedReader" /> 

      

        
        
        
      

    

The end result is this:

The top half is the FlowDocumentReader which I use for debugging. Everything is fine here. The bottom half is the DocumentViewer containing my paginated document, which is what I need to get it working properly.

How to accurately store anchor data through the pagination process?