private void GetResourceSet()
{
    this.ResourceSet = Request.Form[this.lstResourceSet.UniqueID];
    if (ResourceSet == null)
        this.ResourceSet = Request.QueryString["ResourceSet"];
    if (this.ResourceSet == null)
        this.ResourceSet = ViewState["ResourceSet"] as string;
 
    if (this.ResourceSet == null)
        this.ResourceSet = "";
 
    this.ResourceSet = this.ResourceSet.ToLower();
 
    if (!string.IsNullOrEmpty(this.ResourceSet))
        ViewState["ResourceSet"] = this.ResourceSet;
 
    // *** Clear selections
    //lstResourceIds.Items.Clear();
    lstResourceIds.ClearSelection();
 
    lstResourceSet.Items.Clear();
    lstResourceSet.ClearSelection();   
 
    DataTable dt = Manager.GetAllResourceSets(ResourceListingTypes.AllResources);
    this.lstResourceSet.DataSource = dt;
    this.lstResourceSet.DataValueField = "ResourceSet";
 
    try
    {
        this.lstResourceSet.DataBind();
    }
    catch 
    { 
        // *** Works with this hack. Without exception block it
        //     fails with SelectedValue could not be assigned. With it
        //     re-binding works.
        //
        // this fails for some unknown reason on rebinds (off a btn submission)
        // which in effect rebinds an already bound list.
        //
        // First pass through always works fine - only rebind fails.
        //
        // complains about SelectedValue being set to a value
        // that doesn't exist even though selection is already
        // cleared AND the value that it actually is set after
        // DataBind() DOES exist in the data.
    }
 
    if ( !string.IsNullOrEmpty(this.ResourceSet) )
        this.lstResourceSet.SelectedValue = this.ResourceSet;
    else
    {
        if (this.lstResourceSet.Items.Count > 0)
        {
            this.ResourceSet = this.lstResourceSet.Items[0].Value;
            this.lstResourceSet.SelectedValue = this.ResourceSet;                    
        }
    }
}