New Post: OxyPlot.WPF.RectangleAnnotation no text when using code

We are converting over from the 1.3 version to 2.0. In 1.3 we had made a WPF version from LineAnnotation which work ok but we are trying to use the supplied 2.0 version.
The rectangle shows with the correct outline color and fill color in the right location but no text.
Plot has a DateTimeAxis at the bottom, normal vertical axis on left.
We are using the following:

                ra = new OxyPlot.Wpf.RectangleAnnotation();
                ra.MinimumX = OxyPlot.Axes.DateTimeAxis.ToDouble(ll);
                ra.MaximumX = OxyPlot.Axes.DateTimeAxis.ToDouble(llW);
                ra.MinimumY = yBot;
                ra.MaximumY = yTop;
                ra.Fill = Colors.White;
                ra.Stroke = Colors.Black;
                ra.StrokeThickness = 2;
                ra.ClipToBounds = false;
                ra.Text = " Case Colors";
                ra.Layer = AnnotationLayer.AboveSeries;
                ra.TextRotation = 0.0;
                CaseComparePlot.Annotations.Add(ra);

Any suggestions on what's missing?