Round Graduation Values on Chart axis after a zoom

[Gualino]

Hi all, I have a chart on which X axis goes from -2.0 to +2.0. When I zoom in, X axis values turn to -1.65987785798675764658;+0.987687570998687576

I have tried this:

Private Sub RoundChartAxis() Handles YMDChart.AxisViewChanged
        YMDChartArea.AxisX.RoundAxisValues()
    End Sub

Also, when I zoom in, scrollbars appear, ans the X axis one takes only 3 position Left, Middle, Right... Thanks in advance!