RangeValidator e controllo calendar, strano problema

[djciko]

cosi' mi funziona

 <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="tb" runat="server"></asp:TextBox>
        <asp:RangeValidator Display="Dynamic" ID="rv" runat="server" ControlToValidate="tb"
            ErrorMessage="Range Errato - Entro 14 gg" Type="Date"></asp:RangeValidator>
    </div>
    <br />
    <asp:Calendar ID="calendar1" runat="server" OnSelectionChanged="calendar1_SelectionChanged">
    </asp:Calendar>
</form>

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If Not IsPostBack Then
            rv.MinimumValue = DateTime.Now.ToShortDateString()
            rv.MaximumValue = DateTime.Now.AddDays(14).ToShortDateString()
        End If

        Response.Write("Puoi scegliere una data che va dal " + rv.MinimumValue.ToString() + " al " + rv.MaximumValue.ToString())
    End Sub




    Protected Sub calendar1_SelectionChanged(sender As Object, e As EventArgs) Handles calendar1.SelectionChanged
        tb.Text = calendar1.SelectedDate
        Me.Validate()
    End Sub