Problem dragging Winforms TreeNode to WPF List

Question

I'm having some problems dragging a WinForms TreeNode to a WPF ListBox. I set the ListBox.AllowDrop = true and subscribe the DragEnter and Drop events. The events are raised when they should but I think the Args are a bit messed up.

I'm trying to filter the objects that can be dropped into this specific target. I just started by trying to disallow every object by setting the DragDropEffects = DragDropEffects.None but it just isn't working.

Is this a question of interoperability between WinForms and WPF or am I doing something wrong?

Here is the XAML for the Listbox:

<ListBox Name="itmCtrlSetupSteps" Grid.Row="1"
    BorderThickness="2" BorderBrush="{Binding DropBrush}" Background="Transparent"
    ItemsSource="{Binding SetupSteps}" SelectionMode="Single" ItemContainerStyle="{StaticResource StepItemStyle}"
    HorizontalContentAlignment="Stretch"                          
    SelectionChanged="manageStep_SelectionChanged"
    AllowDrop="True" DragEnter="itmCtrls_DragEnter" Drop="itmCtrls_Drop"
/>

And here is the code for the DragEnter event handler:

private void itmCtrls_DragEnter(object sender, DragEventArgs e)
{
    e.Effects = DragDropEffects.None;
    e.Handled = true;
}