problem with deleting Appointments

[Alessandro]

hi, i can't delete appointments.. in debug mode i never enter the function
here's the RadScheduler code in aspx

<telerik:RadScheduler runat="server"
ID="RadScheduler1"
 Width="1000px"
    SelectedDate="01-01-2011"
     TimeZoneOffset="03:00:00"
     DayStartTime="08:00:00"
     DayEndTime="18:00:00"
    StartEditingInAdvancedForm="false"
     DataKeyField="ID"
      DataSubjectField="Subject"
    DataStartField="Start"
     DataEndField="End"
      DataRecurrenceField="RecurrenceRule"
     OnFormCreating="RadScheduler1_FormCreating"
    DataRecurrenceParentKeyField="RecurrenceParentID"
    Skin="WebBlue" Culture="it-IT" FirstDayOfWeek="Monday"
    LastDayOfWeek="Friday" SelectedView="WeekView"
    OnAppointmentDelete="RadScheduler1_OnAppointmentDelete"
    AppointmentStyleMode="Simple" OnAppointmentDataBound="RadScheduler1_AppointmentDataBound" AllowDelete="true" OnClientAppointmentDeleting="onAppointmentDeleting"
  >

and the function

protected void RadScheduler1_OnAppointmentDelete(object sender, SchedulerCancelEventArgs e)

{

    // I never go in this function

}

i also set proprietyAllowDelete="true"
i cant' understand why the event don't run.

thanks
Ale