Use the code snippet:

    Sub New()

        InitializeComponent()
        Me.RadSpinEditor1.EnableNullValueInput = True
        Me.RadSpinEditor1.NullableValue = Nothing

        Console.WriteLine("Value " & Me.RadSpinEditor1.Value & " END")
        Console.WriteLine("NullableValue " & Me.RadSpinEditor1.NullableValue & " END")
    End Sub

    Private Sub RadSpinEditor1_NullableValueChanged(sender As Object, e As EventArgs) Handles RadSpinEditor1.NullableValueChanged
        Console.WriteLine("NullableValueChanged " & Me.RadSpinEditor1.NullableValue & " END")
    End Sub

Follow the steps:

1. Run the project with the above code and enter 0 in the spin editor. Navigate to the next control. You will notice that the NullableValueChanged event doesn't get fired.

2. Focus the spin editor again and enter 5. Navigate to the next control. The NullableValueChanged event is fired as expected.

3. Focus again the spin editor, select the text and press Del. Navigate to the next control. The NullableValueChanged event is fired again as expected.

4. Focus again the spin editor and enter 0. Navigate to the next control. You will notice that the NullableValueChanged event is fired.

5. Focus again the spin editor, select the text and press Del. Navigate to the next control. The NullableValueChanged event is fired again as expected.

6. Focus again the spin editor and enter 0. Navigate to the next control. You will notice that the NullableValueChanged event is NOT fired in this case.