bug on calendar control

the following code raises an exception when we quit the application.

 

Exception

 

"An unhandled exception of type 'System.NullReferenceException' occurred in
wx.net.dll

 

Additional information: Object reference not set to an instance of an
object."

 

Code

 

using System;

using System.Drawing;

using wx;

 

namespace wx.Samples

{

      public class MyFrame : wx.Frame

      {

            public const int ID_DATETIMEPICKER1 = 1;

            CalendarCtrl dateTimePicker1;

 

            public MyFrame(string title, Point pos, Size size) : base(title,
pos, size)

            {

 

                  dateTimePicker1 = new CalendarCtrl(this,
ID_DATETIMEPICKER1, DateTime.Now, new Point(208, 72), new Size(192, 20));

 

            }

      }

 

      // Define a new   application type, each program should derive a class
from App

      public class MyApp : wx.App

      {

 

            public override bool OnInit()

            {

                  MyFrame frame = new MyFrame("Form1", new Point(50,50), new
Size(536,415));

                  frame.Show(true);

                  return true;

            }

 

            [STAThread]

            static void Main()

            {

                  MyApp app = new MyApp();

                  app.Run();

            }

      }

}