thanks Hubert for your time :)
look like Hubert didn't find any weird problem in the code, so we are back
to the issue.
The problem is known.. it's that getRealPath() must return
(rootFolder+context)
but for JSP and servlet to work, we need to setRootFolder(rootfolder).
is it a bug that just been found (that could break API ? )
I would like that we talk about this one to close it asap.