[TYPO3] TV "Container for Elements" problem

[Sébastien Ioannitis-McColl]

Hello
 
I am building a DS, kind of like this:
 
CO   Root
   CO    Header
      EL   Logo
      EL   Generic Menu
      EL   Title
      ...
   CO    Content              ==> field_content
      EL   Text area
      EL   Menu
      ...
   CO    Footer
      EL ...
      ...
 
So I use "Container for elements". Only problem is that it does not seem to work, it kind of only recognizes the field: "field_content" as a container, and when I view my site, it got rid of all other "container for elements" parts.
 
If any idea, thanks to let me know.
 
Seb