Problem with items Adding and Items Added and delete Cascade

Question

I try to add a Lookup field. But in items adding it give me a one before last element of lookup field. In Items Added it works good, but i prefer to use a Items Adding, to then refresh site. Please help me how can I put a cascade lookup in Items Adding Event Receiver. Here is a Code:

                           else
                       {
                           SPListItem item = lstOtherList.Items.Add();
                           item["Kontrakt"] = properties.AfterProperties["Kontrakt1"];
                           item["Pracownik"] = properties.UserDisplayName;
                           item["Dzien"] = dzienStart;
                           item["Procenty"] = properties.AfterProperties["Procenty"];
                           SPList listaWpisy = properties.Web.Lists["Wpisy"];
                           SPListItemCollection listaKontrakty = listaWpisy.Items;
                           foreach (SPListItem kontrakt in listaKontrakty)
                           {
                               item["ID Czas Pracy Wpisy"] = new SPFieldLookupValue(kontrakt.ID, kontrakt.ID.ToString());
                           }
                           dzienStart = dzienStart.AddDays(1.0);

                           item.Update();