You can workaround this in two ways:
1. Tell the Y axis to always place the labels inside its ruler range - this is achieved by the following code:
NLinearScaleConfigurator scaleY = (NLinearScaleConfigurator)chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator;
scaleY.LabelStyle.KeepInsideRuler = true;
2. Specify some top margin:
chart.Margins = new NMarginsL(0, 7, 0, 0);
Hope this helps - let us know if you meet any problems or have any questions.
Nevron Support Team