Error when opening tab for 2nd time

Hi guys,

i have two tabs one is expiry date and block. my problem is, when i click block tab for 1st time it will correctly populate the datagridview. but when i click expiry date tab then block tab again, i got this error 'Provided column already belongs to the DataGridView control.'

attached is my coding.

 Private Sub PopulateAccess()

  Dim sQuery As String = "SELECT Cards.CardNo AS [Card No], Personnel.Name AS [Name], Cards.Expiry_Date AS [Door & Lift Expiry Date], CP_Card.ExpiryDate AS [Car Park Expiry Date], " & _
                            "Cards.AccTag AS [Door Access Rights], Cards.LiftAccTag AS [Lift Access Rights], Personnel.StaffNo, CP_Card.SendBit " & _
                            "FROM Cards LEFT OUTER JOIN Personnel ON Cards.StaffNo = Personnel.StaffNo " & _
                            "LEFT OUTER JOIN CP_Card ON Cards.CardNo = CP_Card.CardNo " & _
                            "ORDER BY Cards.CardNo "
        Dim dsAccess As New DataSet()
        Dim DBClass As New clsDB.clsDatabase
        DBClass.DBServer = DBPath

        Try

            If Not DBClass.ExecuteSQLTable(sQuery, dsAccess) Then
                MsgBox("Unable to retrieve information from database!", MsgBoxStyle.Exclamation, frmTitle)
                LOG.WriteErrLog(0, "fBlock_Extend - PopulateAccess : Failed to retrieve info from database <" & sQuery & ">")
                Exit Sub
            End If

            With dsAccess.Tables(0)
                .Columns.Add("Car Park Access Rights")

                If .Rows.Count > 0 Then
                    ReDim SearchList(.Rows.Count - 1)
                    ReDim aStfNo(.Rows.Count - 1)

                    For icnt As Integer = 0 To .Rows.Count - 1
                        For jcnt As Integer = 0 To .Columns.Count - 1

                            If jcnt = 1 Then
                                .Rows(icnt).Item(jcnt) = Trim(.Rows(icnt).Item(jcnt))

                            ElseIf jcnt = 2 Or jcnt = 3 Then
                                If .Rows(icnt).Item(jcnt) Is Convert.DBNull Then
                                    .Rows(icnt).Item(jcnt) = "-"
                                Else
                                    .Rows(icnt).Item(jcnt) = Mid(.Rows(icnt).Item(jcnt), 7, 2) & "/" & _
                                                            Mid(.Rows(icnt).Item(jcnt), 5, 2) & "/" & _
                                                            Mid(.Rows(icnt).Item(jcnt), 1, 4)
                                End If

                            ElseIf jcnt = 4 Then
                                .Rows(icnt).Item(jcnt) = GetDoorAccess(Trim(.Rows(icnt).Item(0)))
                                If .Rows(icnt).Item(jcnt) = "" Then
                                    .Rows(icnt).Item(jcnt) = "-"
                                End If

                            ElseIf jcnt = 6 Then
                                .Rows(icnt).Item(jcnt) = Trim(.Rows(icnt).Item(jcnt))
                                aStfNo(icnt) = .Rows(icnt).Item(jcnt)

                            ElseIf jcnt = .Columns.Count - 2 Then
                                If .Rows(icnt).Item(jcnt) Is Convert.DBNull Then
                                    .Rows(icnt).Item(jcnt + 1) = "-"
                                Else
                                    .Rows(icnt).Item(jcnt + 1) = GetCPAccess(Trim(.Rows(icnt).Item(0)))
                                End If

                            Else
                                If .Rows(icnt).Item(jcnt) = "" Then
                                    .Rows(icnt).Item(jcnt) = "-"
                                Else
                                    .Rows(icnt).Item(jcnt) = Trim(.Rows(icnt).Item(jcnt))
                                End If
                            End If

                        Next
                    Next
                End If
                .Columns.Remove("SendBit")
                .Columns.Remove("StaffNo")

            End With

            dgvBlock_Acc.DataSource = dsAccess.Tables(0)

            addCheckBox()

        Catch ex As Exception
            LOG.WriteErrLog(0, "Block & Extend - Populate Access : " & ex.Message)
        Finally
            DBClass.Close()
        End Try

    End Sub

Private Sub addCheckBox()

        Try
            Dim chk As New DataGridViewCheckBoxColumn
            dgvBlock_Acc.Columns.Insert(5, chk)

            Dim chk2 As New DataGridViewCheckBoxColumn
            dgvBlock_Acc.Columns.Insert(7, chk2)

            Dim chk3 As New DataGridViewCheckBoxColumn
            dgvBlock_Acc.Columns.Insert(9, chk3)

            For i As Integer = 0 To dgvBlock_Acc.RowCount - 1
                If dgvBlock_Acc.Rows(i).Cells(4).Value <> "-" Then
                    dgvBlock_Acc.Rows(i).Cells(5).Value = True
                End If
                If dgvBlock_Acc.Rows(i).Cells(6).Value <> "-" Then
                    dgvBlock_Acc.Rows(i).Cells(7).Value = True
                End If
                If dgvBlock_Acc.Rows(i).Cells(8).Value <> "-" Then
                    dgvBlock_Acc.Rows(i).Cells(9).Value = True
                End If
            Next

        Catch ex As Exception
            LOG.WriteErrLog(0, "frmBlockExt - Add check box : " & ex.Message)
        End Try
       

    End Sub

so how i'm gonna solve this error?

thanx in advance.