[Calc] Listener on cell change - Going in circle

Hi,

I use easy examples on ’ how to listen event on cel modified’.

I just put an MsgBox in the sub called but the issue is the next :

When i load the file and modify a cell, the sub is correctly called and show me the msgbox, but if i modify another cell (or the same), the sub is called twice … and if i modify again another cell (or the same) the sub is called three times and so on and so on …

So i think that something is buffered somewhere … but what and where i don t know …

Is there a way to empty the listener or something else ?

Thx anymay for all the responses u can give.

Edited for adding code :

    global PysClass as Object
global PysListener as Object

sub main
	PysListenersAdd
end sub

Sub PysListenersAdd
   PysClass= thisComponent.Sheets.getByName("Effectifs")
   PysListener = CreateUnoListener( "Pys_", "com.sun.star.util.XModifyListener" )   
   PysClass.AddModifyListener(PysListener)
End Sub

Sub PysListenersRemove
  PysClass.RemoveModifyListener(PysListener)
End Sub

Sub Pys_Modified(oEvent)
   PysListenersRemove()
   MarkForChange(oEvent)
   PysListenersAdd()
end sub

Sub Pys_Disposing
End Sub

Sub MarkForChange(evt)
  	Dim laCellule As Object, CelluleActive As Object, dispatcher as object, document as object
	dim en_cours as integer
	
	laCellule = evt.Source
	'MsgBox ecouteurCellule.DBG_Properties
	'MsgBox ecouteurCellule.DBG_methods	
 	' MsgBox("Cellule : " & laCellule.AbsoluteName & chr(13) & "Valeur : " & laCellule.value & chr(13) & "Texte : " & laCellule.string & chr(13) & "Formule : " & laCellule.FormulaLocal)
 	
 	CelluleActive = ThisComponent.getCurrentController.selection
 	if CelluleActive.supportsService("com.sun.star.sheet.SheetCell") then
 	 	if CelluleActive.string = "" then
			en_cours =  CelluleActive.CellAddress.row
			oLigne = oFeuille.getRows.getByIndex(en_cours)
			thisComponent.currentController.select(oLigne)
			oFeuille.getRows.removeByIndex(en_cours,1)
			redim laCellule
			Exit Sub
 	 	end if
 	 	if CelluleActive.string <> "" then 
 	 		MsgBox "New !!!"
			redim laCellule
 	 		Exit Sub
 	 	end if
 	end if
End Sub