Hi,

The type of the ImageAlign property is the ImageAlign enumeration, which does not contain a None member. Doesn't VB.NET show some kind of warning when you try to assign that value? Stretch.None might not have a corresponding value in ImageAlign, and then the image alignment code would get skipped. In any case, you can see the supported values here:
http://www.mindfusion.eu/onlinehelp/diagramlite/index.htm?T_MindFusion_Diagrammi...

Also if you are resizing the diagram to match the zoom level, you might have to resize the background node too by setting backnode.Bounds = diagram.Bounds.

I hope that helps,
Stoyan

This works in my test:

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
	var backNode = diagram.Factory.CreateShapeNode(diagram.Bounds);
	backNode.ImageAlign = ImageAlign.Stretch;
	backNode.Image = new BitmapImage(new Uri(
		"test_image.jpg", UriKind.Relative));
	backNode.Locked = true;
}

private void OnDoubleSize(object sender, RoutedEventArgs e)
{
	var newBounds = diagram.Bounds;
	newBounds.Width *= 2;
	newBounds.Height *= 2;
	diagram.Bounds = newBounds;
	diagram.Nodes[0].Bounds = newBounds;
}