Hi, All!

I want to write a function in Mathematica 9 that opens and closes all sections in my notebook. I do it as follows:

openCloseAll[nb_, target_String, to : (Open | Closed)] := 
 Do[SelectionMove[cell, All, CellGroup, AutoScroll -> False];
  With[{content = 
     Block[{$Context = "FrontEnd`", $ContextPath = {"System`"}}, 
      NotebookRead[nb]], from = to /. {Closed -> Open, Open -> Closed}}, 
   If[MatchQ[content, Cell[CellGroupData[{Cell[_, target, ___], __}, from]]], 
    NotebookWrite[nb, Cell[CellGroupData[content[[1, 1]], to]], 
     AutoScroll -> False]]];, {cell, Cells[CellStyle -> target]}]

Then I create two buttons to deal with sections:

Button["Close sections", openCloseAll[EvaluationNotebook[], "Section", Closed]]

and

Button["Open sections", openCloseAll[EvaluationNotebook[], "Section", Open]]

At last, I create a section with a single cell in it (a comment between two expressions - it is important!):

something1
(*a comment*)
something2

The resulting file attached below is the first notebook. When I push successively "Close sections" and "Open sections" buttons, I see a garbage in the section instead of the first two lines of the cell (see the second attached file). What happens?

Attachments:

open_close_problem.nb

open_close_probl...nb