Why, o why does this cause eratic behaviour in my (bound) maskedtextbox(es)?

Is there a fatwa against maskedtexboxes that I should know of?

    Protected Overrides Sub OnKeyPress(ByVal e As KeyPressEventArgs)
        ' http://www.syncfusion.com/FAQ/windowsforms/faq_c94c.aspx#q1121q
        If e.KeyChar = Chr(13) Then 'CChar(13)
            e.Handled = True
        Else
            MyBase.OnKeyPress(e)
        End If
    End Sub

Thanks.

Marc

PS : I need this so to disable the beep each time the user completes a field with the enter key.