Query in a thread

I have 3 comboboxes that are loaded with data from LINQ queries on page load. The problem is that queries contain so much data that it causes Internet Explorer to stop responding for a bit more than a minute.

As there are 3 queries my idea is to put them in 3 different threads, but the problem is at the end the only thing I get is the error saying: "Both DataSource and DataSourceID are defined on 'cbOrganizator'. Remove one definition."

cbOrganizator is a combobox.

Here is the code:

protected void Page_Load(object sender, EventArgs e)
{
    Bind();
}

public void Osobe()
    {
        PravosudnaAkademijaEntities db = new PravosudnaAkademijaEntities();

        var osoba = from o in db.osobas
                    orderby o.osoba_prezime
                    select new { o.osoba_id, imePrezime = o.osoba_prezime + " " + o.osoba_ime + " | " + o.tijelo.tijelo_naziv + " | " + o.radno_mjesto.rm_naziv_m };

        cbPolaznik.DataSource = osoba;
        cbPolaznik.DataTextField = "imePrezime";
        cbPolaznik.DataValueField = "osoba_id";
        cbPolaznik.DataBind();
        cbPolaznik.Items.Insert(0, " ");

        cbPredavac.DataSource = osoba;
        cbPredavac.DataTextField = "imePrezime";
        cbPredavac.DataValueField = "osoba_id";
        cbPredavac.DataBind();
        cbPredavac.Items.Insert(0, " ");

        cbAOM.DataSource = osoba;
        cbAOM.DataTextField = "imePrezime";
        cbAOM.DataValueField = "osoba_id";
        cbAOM.DataBind();
        cbAOM.Items.Insert(0, " ");
    }

    public void Tijela()
    {
        PravosudnaAkademijaEntities db = new PravosudnaAkademijaEntities();

        var tijelo = from t in db.tijeloes
                     orderby t.tijelo_naziv
                     select new { t.tijelo_id, sve = t.tijelo_naziv + " | " + t.mjesto.zupanija_drzava.zupanija_naziv };

        cbOrganizator.DataSource = tijelo;
        cbOrganizator.DataTextField = "sve";
        cbOrganizator.DataValueField = "tijelo_id";
        cbOrganizator.DataBind();
        cbOrganizator.Items.Insert(0, " ");
    }

    public void Bind()
    {
         Thread tOsobe = new Thread(Osobe);
         tOsobe.Start();
         Thread tTijela = new Thread(Tijela);
         tTijela.Start();
    }

I don't know what's wrong so any help would be appreciated. The primary idea is to separate queries into threads so if my approach is wrong please let me know.

You're starting threads but not giving them a chance to finish before the page is loaded. I don't know how that results in your particular error, but if your page loads before the thread is completed, then you definitely won't get results.

I really don't see how you'll be able to accomplish what you're trying to do without AJAX.