In the application I am writing I open a dialog window for entry of
value pairs via combobox selections that are added to a grid on that
form.  The items in the grid can be removed as well.  The problem I am
having is when the window is closed and then re-opened an added item
row doesn't appear in the grid.  If the window is closed and re-opened
the new row will appear.

Here is code from the Form Load event:

        Dim tableStyle As New DataGridTableStyle
        tableStyle.MappingName = "sample_area"

        Dim column As New DataGridTextBoxColumn
        column.MappingName = "district"
        column.HeaderText = "District"
        column.Width = 100
        tableStyle.GridColumnStyles.Add(column)

        column = New DataGridTextBoxColumn
        column.MappingName = "subdistrict"
        column.HeaderText = "SubDistrict"
        column.Width = 100
        tableStyle.GridColumnStyles.Add(column)

        tableStyle.MappingName = "sample_area"

        With grdAreas
            .ColumnHeadersVisible = True
            .TableStyles.Add(tableStyle)
        End With

        grdAreas.DataSource = gdsData.Tables("sample_area")

The Add Event:

        Dim dr As System.Data.DataRow
        dr = gdsData.Tables("sample_area").NewRow
        dr.Item("year") = gstrCWTYear
        dr.Item("sample") = gstrSampleNumber
        dr.Item("district") = cboDistrict.Text
        dr.Item("subdistrict") = cboSubdistrict.Text
        gdsData.Tables("sample_area").Rows.Add(dr)

In the remove event I find the row in the dataset and issue a

        gdsData.Tables("sample_area").Rows(rowIndex).Delete

The very first time the window is opened everything seems to work fine
but if the window is closed:

    Private Sub btnOk_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnOk.Click
        Me.Close()
    End Sub

And then opened:

            Dim f As New frmArea
            f.ShowDialog()

The grid will not display a new "addition".

I have tried refresh but the only thing that seems to work is setting
the datasource of the grid to nothing and then  set it back to the
dataset's datatable.  This; however, just doesn't seem right.

Does anyone have any idea what I am doing wrong?