Web Forms :: DropDownList In Visual Studio 2010 - OnChangeEvent Does Not Work?

I am using code I have always used in other version of VS for binding to a list box.

After binding a dataset to a ListBox in VS 2010, render the page, and cilck any item in the list, the on change event always goes back to the first item in the list!

The following code to run the list box runs once...

if (!Page.IsPostBack)
DataSet ds = UWA.AWHWebServices.GetAllBranches();
LBCSC.DataSource = ds;
LBCSC.DataTextField = "BUSN_ROLE_NM";
LBCSC.DataValueField = "BUSN_ROLE_TYP_CD";
LBCSC.DataBind();

Now instead if I load the list box using Items.add, render the page, and then click on any item in the list I get the correct item selected.

for (int i=0;i<ds.Tables[0].Rows.Count; i++){ LBCSC.Items.Add(ds.Tables[0].Rows[i] "BUSN_ROLE_NM"].ToString());}

Is this a VS 2010 Bug?