VB.NET Insert ข้อมูลใน Access แล้วสั่ง Re-load ข้อมูลใน DataGridView แล้วไม่ทำงานเป็นบางครั้ง

 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        LoadSetupData()
    End Sub

    Private Sub LoadSetupData()

        Dim daSetup As OleDb.OleDbDataAdapter
        Dim cmdSetup As OleDb.OleDbCommand
        Dim ds As New DataSet()

        ConnectDB()
        cmdSetup = New OleDb.OleDbCommand(String.Format("SELECT * FROM Employees Order by Firstname"), conn)
        daSetup = New OleDb.OleDbDataAdapter(cmdSetup)
        daSetup.Fill(ds, "tbEmp")
        dgData.DataSource = ds
        dgData.DataMember = "tbEmp"

    End Sub

    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click

        Dim cmdSave As OleDbCommand
        Dim strSave As String

        strSave = "Insert Into Employees (Firstname,LastName) Values ('" & txtFname.Text & "','" & txtLname.Text & "')"

        Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\EmployeeDB.mdb;User Id=;Password=;"
        conn = New OleDb.OleDbConnection(strConn)
        conn.Close()
        conn.Open()

        Try
            cmdSave = New OleDbCommand(strSave, conn)
            cmdSave.ExecuteNonQuery()

            cmdSave.Dispose()
            dgData.DataSource = Nothing
            Call LoadSetupData()                        'สั่ง re-load data จาก table ใหม่
        Catch ex As Exception
            MessageBox.Show(ex.Message.ToString, "Message", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try

    End Sub