I have a BeforeDropDown Event for Ultracombo, where I load the data and bind to the UltraCombo

The problem is that the current value displayed disappears.

here is a small winforms test program I created

        private DataTable datatable;
        public Form1()
        {
            InitializeComponent();

            this.ultraCombo1.Text = "1";
            this.ultraCombo1.BeforeDropDown += new  CancelEventHandler(ultraCombo1_BeforeDropDown);
        }


        void ultraCombo1_BeforeDropDown(object sender, CancelEventArgs e)
        {
            datatable = new DataTable("COMPMS0");
            datatable.Columns.Add("Company", typeof(int));
            datatable.Columns.Add("Company description", typeof(string));
            datatable.Rows.Add("9", "Nine");
            datatable.Rows.Add("17", "Seventeen");
            datatable.Rows.Add("1", "ZZZZ");
            datatable.Rows.Add("3", "Three");
     
            this.ultraCombo1.DataSource = datatable;
        }

help is appreciated