Exporting to Excel from DataGridView terminates at null cell entry

[pel11]

I noticed that when I export to Excel from a DGV, the export leaves out cells to the right and below an empty cell (with Nothing or Null in it), i.e., terminates at that cell. I am using a dbNull trap, so is there something I am missing?

       Dim dgv As DataGridView = CType(TabControl2.TabPages(1).Controls("dgv1"), DataGridView)
       Dim dt As New DataTable()

        'Adding the Columns
        For Each column As DataGridViewColumn In dgv.Columns
            dt.Columns.Add(column.HeaderText, column.ValueType)
        Next

        'Adding the Rows
        Try
            For Each row As DataGridViewRow In dgv.Rows
                dt.Rows.Add()
                For Each cell As DataGridViewCell In row.Cells
                    If cell.Value IsNot Nothing Then
                        dt.Rows(dt.Rows.Count - 1)(cell.ColumnIndex) = cell.Value.ToString()
                    End If
                    If IsDBNull(cell.Value) Then
                        dt.Rows(dt.Rows.Count - 1)(cell.ColumnIndex) = ""
                    End If
                Next
            Next
        Catch
        End Try

        'Exporting to Excel
        Try
            Using wb As New XLWorkbook()
                wb.Worksheets.Add(dt, RunName)
                wb.SaveAs(SaveFilename)
                wb.Dispose()
            End Using
            dt.Dispose()
        Catch
            System.Windows.Forms.MessageBox.Show("You have the the export file open in Excel. Please close the file, and then retry exporting.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
            Exit Sub
        End Try