Is there a bug with ...LineChart.NullHandling = NullHandling.DontPlot ?

I am adding NumericSeries into a MRUltraChart Class inherited from Ultrachart. Somehow, some of the icons in the lineChart are not displaying although I have ensured that all data are displayed in the NumericSeries. I am adding all data into each NumericSeries and using the

NS1.Points.Add(New NumericDataPoint(ChlaValue, AMTD, True)) OR  NS1.Points.Add(New NumericDataPoint(ChlaValue, AMTD, False)) to display empty/null values or not. In my MRUltraChart I have set Me.LineChart.NullHandling = NullHandling.DontPlot to hide datapoints (i.e. icons) I do not wish to display.

Somehow, for example out of 11 data in the NumericSeries (NS1) I have 8 data points that need to be shown (i.e. NS1.Points.Add(New NumericDataPoint(ChlaValue, AMTD, False)) ) and the rest set to NS1.Points.Add(New NumericDataPoint(ChlaValue, AMTD, True)) to show as null value. When displaying my Chart however, only 7 points are shown.

P.S. To make sure I have not missed a data points, I have loop through all data points in the NumericSeries NS1 and shown correct null values and "Empty" fields.

How to get this bug fixed?

Public Class MRultrachart

Inherits Infragistics.Win.UltraWinChart.UltraChart

Public Sub New(ByVal width As Integer, ByVal height As Integer)

Me.Size = New Drawing.Size(width, height)

Me.BorderStyle = Windows.Forms.BorderStyle.None

Me.Border.Thickness = 0

Me.LineChart.NullHandling = NullHandling.DontPlot 'null points won't be displayed

With AxisDim axisMargn As New Infragistics.UltraChart.Resources.Appearance.AxisMargin

axisMargn.MarginType = Infragistics.UltraChart.Shared.Styles.LocationType.Pixels

axisMargn.Value = 4

.X.Margin.Far = axisMargn

.X.Margin.Near = axisMargn

.Y.Margin.Far = axisMargn

.Y.Margin.Near = axisMargn

.Y.TickmarkStyle = Infragistics.UltraChart.Shared.Styles.AxisTickStyle.Smart

.X.Labels.Orientation = Infragistics.UltraChart.Shared.Styles.TextOrientation.Horizontal

.Y.Labels.Orientation = Infragistics.UltraChart.Shared.Styles.TextOrientation.Horizontal

.X.Extent = 3

.Y.Extent = 12

.X.LineThickness = 1

.Y.LineThickness = 1

.X.MajorGridLines.Visible = False

.Y.MajorGridLines.Visible = False

.X.Labels.Font = New Font("Arial", 7, FontStyle.Regular, GraphicsUnit.Point) .Y.Labels.Font = New Font("Arial", 7, FontStyle.Regular, GraphicsUnit.Point)

.Y.Labels.ItemFormatString = "<DATA_VALUE:0.#>" 'somehow not working; -> so have to set onPrintDocument procedure

End With

End Sub

End Class