DGV Validation Error When Bindingsource is Sorted

I’m having a problem with a datagridview that is bound to an Access table.  If the bindingsource is sorted, the wrong dgv value is validated – this occurs randomly and I cannot force the failure.  It appears that, after I enter a new cell value and prior to validation, the dgv is re-sorted and the cell value immediately above the cell I just changed is used for the validation.

If a disable sorting, I do not have any problems with validating the cell.

Below is the code I use to bind the table to the dgv and my cell validation routine.

'**********************************************************

    Dim ds_Dataset As New DataSet("SE_Dataset")
    Dim dt_Names As DataTable = ds_Dataset.Tables.Add(Me.Name)
    Dim da_Names As OleDbDataAdapter = New OleDbDataAdapter
    Dim bs_Names As New BindingSource

'**********************************************************

    Private Sub Table_Bind()

        Dim str_SQL As String = "SELECT * " & _
                                "FROM tbl_SE_DS_Path_Names"
        cmd = New OleDb.OleDbCommand(str_SQL, con_SE_MDB)
        da_Names = New OleDbDataAdapter(cmd)
        Dim commandBuilder As New OleDbCommandBuilder(da_Names)
        da_Names.Fill(dt_Names)
        bs_Names.DataSource = dt_Names
        bs_Names.Sort = "Path_Name"

    End Sub

'**********************************************************

Private Sub dgv_CellValidating(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles dgv.CellValidating

    If dgv.IsCurrentCellDirty Then
        dgv.CommitEdit(DataGridViewDataErrorContexts.Commit)
        If Not Validate_Path_Name(dgv.Rows(e.RowIndex).Cells(e.ColumnIndex).Value)) Then
            e.Cancel = True
        Else
            bs_Names.EndEdit()
            da_Names.Update(CType(bs_Names.DataSource, DataTable))
        End If

    End Sub

'**********************************************************

Here is the normal sequence of events with the validation works correctly; ‘zz’ was the original cell value; ‘aa’ is the new cell value:

CellBeginEdit:         Row = 2   Value = zz
CellLeave:             Row = 2   Value = zz
CellValidating:        Row = 2   Value = aa

This is the sequence of events when a validation error occurs.  ‘zz’ was the original cell value, ‘aa’ is the new cell value, ‘www’ was the value in the row immediately above ‘zz’ prior to entering ‘aa’.  Note that I am getting 2 CellLeave and 2 CellEnter events when a validation error is going to occur.

CellBeginEdit:         Row = 2   Value = zz
CellLeave:             Row = 2   Value = zz
CellLeave:             Row = 2   Value = www
CellEnter:             Row = 2   Value = www
CellEnter:             Row = 0   Value = aa
CellValidating:        Row = 2   Value = www

I repeatedly changed the same values in the dgv until a validation error occurred.  I cannot force the error – it’s occurs randomly.

This problem DOES NOT OCCUR if I do not sort bs_names.  I’ve tried sorting the dgv, but the problem still occurs.

Hopefully, I’ve made some sense of what I’m experiencing.  When everything is working correctly, my Access table is updated on each cell change; on the random validation error, the table is not updated.

Any thoughts as to why sorting bs_names (or the dgv) appears to cause random validation errors?

Thank you in advance for your help!

George