Actually, I'm investigating the second option by reading LAM itself.
It will work, but I will have to update all my controls manually.
Pictures to explain:
- first it will be like this:
https://dl.dropboxusercontent.com/u/38282964/1.jpg
- after click:
https://dl.dropboxusercontent.com/u/38282964/2.jpg
- after switching to another panel and comming back:
https://dl.dropboxusercontent.com/u/38282964/3.jpg
I came to the conclusion that I just need to trigger the "OnShow" event on the controls after clicking on the "Open" button.
Happy to have found this :-)