In the example you've posted above, which menu item are translated and which not?
You're right !
The top elements so "Tools" and "Help" are not translated !
It's definitely a bug with Flex !
I added a button outside of the menuBar that changes the language. (click="localeChain=[fr_FR];")
When cilcked, everything including each and every menu items gets translated !
So it is not a problem with my resource bundle.
How can i go arround this bug ?