MS Chart is not displaying exact values

I have a problem. My MSChart is not displaying the exact values on the chart. It looks like it is rounding up and down some of the values ????
Here is the code of the assignment:

MSChart1.ToDefaults
MSChart1.ChartType = VtChChartType2dXY

MSChart1.AllowDithering = False

MSChart1.Plot.UniformAxis = False

MSChart1.RowCount = 49
MSChart1.ColumnCount = 6
MSChart1.ColumnLabelCount = 6
MSChart1.Legend.Location.Visible = True
MSChart1.Legend.Location.LocationType = VtChLocationTypeBottomRight
MSChart1.Legend.VtFont.Style = VtFontStyleBold

MSChart1.Plot.Axis(VtChAxisIdY).CategoryScale.Auto = False
MSChart1.Plot.Axis(VtChAxisIdY).AxisScale.Type = VtChScaleTypeLinear
MSChart1.Plot.Axis(VtChAxisIdY).ValueScale.Auto = False
MSChart1.Plot.Axis(VtChAxisIdY).ValueScale.Minimum = MinY
MSChart1.Plot.Axis(VtChAxisIdY).ValueScale.Maximum = MaxY
MSChart1.Plot.Axis(VtChAxisIdY).ValueScale.MajorDivision = 20

MSChart1.Plot.Axis(VtChAxisIdX).CategoryScale.Auto = False
MSChart1.Plot.Axis(VtChAxisIdX).AxisScale.Type = VtChScaleTypeLinear
MSChart1.Plot.Axis(VtChAxisIdX).ValueScale.Auto = False
MSChart1.Plot.Axis(VtChAxisIdX).ValueScale.Minimum = 1
MSChart1.Plot.Axis(VtChAxisIdX).ValueScale.Maximum = 49
MSChart1.Plot.Axis(VtChAxisIdX).ValueScale.MajorDivision = 8
MSChart1.Plot.Axis(VtChAxisIdX).ValueScale.MinorDivision = 1

MSChart1.ChartData = ChartData
MSChart1.Repaint = True

My data are 3 sets of X and Y, each of them got 49 pairs
ChartData is a variant (49,6), that are assigned as per the following:

Chartdata(x,1)=x values of first set
Chartdata(x,2)=y values of first set
Chartdata(x,3)=x values of second set
Chartdata(x,4)=y values of second set
Chartdata(x,5)=x values of third set
ChartData(x,6)=y values of third set

I am looking at the minimum and maximum values that Y can take (these are MinY and MaxY).

The problem is that the chart shows some values being 0, but looking at the vector they are not ...