title: DDL Second iteration does not 'rest' cascading drop down
body: <p>I have the following code that a cascading drop down kicks off with </p>
  
  <pre><code>protected void ddlBuyer_SelectedIndexChanged(object sender, EventArgs e)
  {
      FinalProductsDataContext dbII = new FinalProductsDataContext();
      var queryBuyer = (from r in dbII.tblOnlineReportingFINALPRODUCTSNEWDEMOs
                        where r.UnitUserfield1 == ddlBuyer.SelectedValue
                        select new { UnitUserfield2 = r.UnitUserfield2 }).Distinct().OrderBy(r =&gt; r.UnitUserfield2);
  
      ddlSub.DataSource = queryBuyer;
      ddlSub.DataTextField = "UnitUserfield2";
      ddlSub.DataValueField = "UnitUserfield2";
      ddlSub.DataBind();
  
      GridView1.Columns.Clear();
  
      tbxProdAC.Text = "";
  
      radSub.Checked = false;
      radProd.Checked = false;
      radProdAC.Checked = false;
  
      radBuyer.Checked = true;
  
      ddlProd.Items.Insert(0, "--Choose Product--");
      ddlSub.Items.Insert(0, "--Choose Sub Category--");
  
  }
  </code></pre>
  
  <p>On it's first run through, this runs perfectly with ddlProd &amp; ddlSub being populated with "--Choose..."</p>
  
  <p>However, if the user changes ddlBuyer, ddlSub, ddlProd and then back to change the ddlBuyer, ddlSub is populated with "--Choose Sub-Category--" but ddlProd remains as the first item they looked at.</p>
  
  <p>How can I get around this?</p>