I am dynamically creating ActiveX controls on WinForms in VS.Net 2003.

While this code works great, the OCX file that serves the Active X
control does not get released until after the application has exited.

This is a fairly significant issue for our software as we are actually
trying to delete the file and replace it with a different copy.  Anyone
have any ideas on what is holding the file open and if there's any way
to get at that object to shut it down?

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace ocxtest
{
    /// <summary>
    /// Summary description for Form1.
    /// </summary>
    public class Form1 : System.Windows.Forms.Form
    {
       private System.Windows.Forms.Button button1;
       private System.Windows.Forms.Button button2;
        private System.ComponentModel.Container components = null;
        public Form1()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
        }
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
           this.button1 = new System.Windows.Forms.Button();
           this.button2 = new System.Windows.Forms.Button();
           this.SuspendLayout();
           //
           // button1
           //
           this.button1.Location = new System.Drawing.Point(432, 16);
           this.button1.Name = "button1";
           this.button1.Size = new System.Drawing.Size(80, 24);
           this.button1.TabIndex = 0;
           this.button1.Text = "button1";
           this.button1.Click += new
System.EventHandler(this.button1_Click);
           //
           // button2
           //
           this.button2.Location = new System.Drawing.Point(432, 56);
           this.button2.Name = "button2";
           this.button2.Size = new System.Drawing.Size(80, 24);
           this.button2.TabIndex = 1;
           this.button2.Text = "button2";
           this.button2.Click += new
System.EventHandler(this.button2_Click);
           //
           // Form1
           //
           this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
           this.ClientSize = new System.Drawing.Size(528, 270);
           this.Controls.Add(this.button2);
           this.Controls.Add(this.button1);
           this.Name = "Form1";
           this.Text = "Form1";
           this.ResumeLayout(false);

       }
        #endregion

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.Run(new Form1());
        }

       private ActiveXControl ax ;

       private void button1_Click(object sender, System.EventArgs e)
       {
           Type t = Type.GetTypeFromProgID("a.ctl");
           ax = new ActiveXControl(t.GUID.ToString());
           this.Controls.Add(ax);
           ax.CreateControl();
       }

       private void button2_Click(object sender, System.EventArgs e)
       {
           this.Controls.Remove(ax);
           ax.Dispose();
           ax = null;
        }
    }
   public class ActiveXControl : System.Windows.Forms.AxHost
   {
       public ActiveXControl(string clsid) : base(clsid)
       {
       }
       protected override void Dispose(bool disposing)
       {
           if (disposing)
           {
               this.ContainingControl  = null;
           }
           base.Dispose (disposing);
       }      
   }
}