Have a look

Public Sub LoadUserCombo(ByRef cbo As ComboBox)
            'Load the combobox
            Dim sSQL As String
            Dim dt As New DataTable()

            'Get the users
            sSQL = " SELECT nlUserID, tUserName "
            sSQL += " FROM Users "
            sSQL += " WHERE (lDeleted = " & oSQLUser.SQLBoolean(False) & ") "
            sSQL += " ORDER BY tUserName "

            Try

                'Open the connection
                oSQLUser.ConnectionString = Constants.SIMON_SQL_Connect
                oSQLUser.OpenDBConnection()

                'Get the datatable
                dt = oSQLUser.GetDataTable(sSQL)

                'Close the connection
                oSQLUser.CloseDBConnection()

                'Bind it to the combobox
                cbo.DataSource = dt
                cbo.DisplayMember = "tUserName"
                cbo.ValueMember = "nlUserID"
                cbo.SelectedIndex = 0

            Catch exp As Exception
                RaiseEvent ErrorRaised(exp.Source, exp.Message)
            End Try

        End Sub

If I dispose of the datatable in this sub then the combobox will not be loaded. Any suggestions?