Form.Text = ""; makes the Form disappear

[MontgomeryBurns]

I call the MyForm's ShowDialog. The window appears for less than 1/2 second then disappears, and I don't know why.

    private void MyForm_Load(object sender, System.EventArgs e)
    {
      Text = "";
    }

If I change the lines above into the following, the problem no longer occurs.

    private void MyForm_Load(object sender, System.EventArgs e)
    {
      Text = " ";
    }

Why this? I thought I could empty Text without any trouble.