Messages Event Handler fired twice

Hi everybody.
I´m working on a script to get a message group automated.
It´s a simple script that creates a new entry in a Numbers sheet to record the participant, date and message sent.
Everything is ok but one Event handler is triggered twice: Active chat room message received.
These are two links that shows the same issue, and weren’t solved.
I have the same issue.
http://macscripter.net/viewtopic.php?id=44582


Is this a bug?
This is my script.

property chat_target : “iMessage;+;chat278029391754081049” --Prueba mensajes
property ruta_libro_numbers : “Macintosh HD:Users:algonra:Library:Mobile Documents:com~apple~Numbers:Documents:actividad-grupo-prueba-mensajes.numbers”

using terms from application “Messages”

on actualizar_numbers(grupo_mensajes, remitente, mensaje)
	if grupo_mensajes is chat id chat_target then
		set nombre_cuenta_remitente to my obtener_nombre_online_cuenta_remitente(remitente)
		set fecha_corta_actual to my obtener_fecha_actual_formato_corto()
		my anadir_nuevo_registro(nombre_cuenta_remitente, fecha_corta_actual, mensaje)
	else
		display notification "Error: " & class of grupo_mensajes
	end if
end actualizar_numbers

on obtener_fecha_actual_formato_corto()
	set fecha_actual to current date
	return short date string of fecha_actual
end obtener_fecha_actual_formato_corto

on obtener_nombre_online_cuenta_remitente(remitente)
	return get handle of remitente
end obtener_nombre_online_cuenta_remitente

on anadir_nuevo_registro(cuenta_online, fecha, mensaje_remitente)
	tell application "Numbers"
		launch
		delay 1
		set libro to open ruta_libro_numbers
		tell libro
			tell first sheet
				tell first table
					if value of cell "A2" is missing value then
						set value of cell "A2" to cuenta_online
						set value of cell "B2" to fecha
						set value of cell "C2" to mensaje_remitente
					else
						set num_filas to count of rows
						set nueva_fila to add row below row num_filas
						set num_fila_a_rellenar to num_filas + 1
						set value of cell ("A" & num_fila_a_rellenar) to cuenta_online
						set value of cell ("B" & num_fila_a_rellenar) to fecha
						set value of cell ("C" & num_fila_a_rellenar) to mensaje_remitente
					end if
				end tell
			end tell
		end tell
		
	end tell
end anadir_nuevo_registro


on received text invitation theText from theBuddy for theChat with withParam
	display notification "received text invitation"
end received text invitation

on received audio invitation theText from theBuddy for theChat with withParam
	display notification "received audio invitation"
end received audio invitation

on received video invitation theText from theBuddy for theChat with withParam
	display notification "received video invitation"
end received video invitation

on received file transfer invitation theFileTransfer with withParam
	display notification "received file transfer invitation"
end received file transfer invitation

on buddy authorization requested theRequest with withParam
	display notification "buddy authorization requested"
end buddy authorization requested

on message sent theMessage for theChat with withParam
	display notification "message sent"
end message sent

on message received theMessage from theBuddy for theChat with withParam
	display notification "message received"
end message received

on chat room message received theMessage from theBuddy for theChat with withParam
	display notification "chat room message received"
	my actualizar_numbers(theChat, theBuddy, theMessage)
end chat room message received

on active chat message received theMessage from theBuddy for theChat with withParam
	display notification "active chat message received"
	my actualizar_numbers(theChat, theBuddy, theMessage)
end active chat message received

on addressed chat room message received theMessage from theBuddy for theChat with withParam
	display notification "addressed chat room message received"
end addressed chat room message received

on addressed message received theMessage from theBuddy for theChat with withParam
	display notification "addressed message received"
end addressed message received

on av chat started with withParam
	display notification "av chat started"
end av chat started

on av chat ended with withParam
	display notification "av chat ended"
end av chat ended

on login finished for theService with withParam
	display notification "login finished"
end login finished

on logout finished for theService with withParam
	display notification "logout finished"
end logout finished

on buddy became available theBuddy with withParam
	display notification "buddy became available"
end buddy became available

on buddy became unavailable theBuddy with withParam
	display notification "buddy became unavailable"
end buddy became unavailable

on completed file transfer with withParam
	display notification "completed file transfer"
end completed file transfer

end using terms from

Thanks very much in advanced