trouble with activex controls

I am trying to teach myself to develop activex controls for embedding in a web page, and I am having some trouble getting the control to appear. I had it working at one point, but then it just stopped working, and I can't figure out what I changed that caused it to stop working.

the following is my C# code verbatim from my project:

Code:

---

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace MyActivexControl
{
    [Guid("6616AE32-2EC0-4B10-9BB2-71679687EBA4"), ClassInterface(ClassInterfaceType.AutoDual)]
    public class MyActivexControl : UserControl
    {
        TextBox txtTestTextBox;
        Button btnTestButton;
        Label lblTestLabel;

        public MyActivexControl()
        {
            InitializeComponent();
        }

        void InitializeComponent()
        {
            this.Size = new System.Drawing.Size(200, 200);

            txtTestTextBox = new TextBox();
            txtTestTextBox.Size = new Size(96, 24);
            txtTestTextBox.Location = new Point(8, 8);
            this.Controls.Add(txtTestTextBox);

            btnTestButton = new Button();
            btnTestButton.Text = "Click Me";
            btnTestButton.Size = new Size(80, 24);
            btnTestButton.Location = new Point(112, 8);
            btnTestButton.Click += new EventHandler(btnTestButton_Click);
            this.Controls.Add(btnTestButton);

            lblTestLabel = new Label();
            lblTestLabel.Size = new Size(96, 24);
            lblTestLabel.Location = new Point(8, 40);
            this.Controls.Add(lblTestLabel);
        }

        private void btnTestButton_Click(object sender, EventArgs e)
        {
            lblTestLabel.Text = txtTestTextBox.Text;
        }
    }
}

---

and the html code for embedding the object:

Code:

---

<div id="myActivexControl">
    <object id="myControl" name="myControl" classid="MyActivexControl.dll#MyActivexControl.MyActivexControl"
            style="width:200px; height:200px; background-color:inherit; font-family:Arial; color:inherit; font-style:inherit; font-size:inherit" />
</div>

---

the assembly file is in the root of the web server (visual studio's integrated server), and like I said, it was working fine before, but then without warning, it stopped working. a placeholder of the correct size appears in the browser, but it's empty.