How to clone invisible a stack?

[André Bisseret]

Bonjour,

I have a main stack (say mainStack1" of which one substack is a model stack, say stack "stackModel"

On an another main stack, I have a button with a mouseUp handler that creates a new stack by cloning the model stack.

When I clone invisible stack "stackModel", that create a stack "copy of stackModel", as expected. 
I rename it.
My problem is that I can't do that invisibly: the clone "Copy of stackModel" is always visible for a while!

that keeps being so, despite the fact that I lock screen.

Trying to set the visible of stack "stackModel" to false before cloning does not help

Below is the involved part of my handler:
--------------
lock screen
---
---
 set the visible of stack "stackModel" of stack "mainStack1" to false -- not better 
 clone invisible stack "stackModel" of stack "mainStack1"
 set the name of it to tNewDoc
--
--
save stack tNewDoc as "bli/bla/blo/tNewDoc
close stack tNewDoc
---------

Any idea on what I am missing?

Thanks a lot in advance for your help

Best regards from Grenoble

André