Just found in the forum using
could be a solution ?
Advices are still welcome :-)
Found the bug. It was because the component was declared with @Scope(ScopeType.CONVERSATION). I set to ScopeType.SESSION), it is working fine now.
It confirms again the rule that says the longer it takes to find a bug, the sillier it must be. And also often it is also because one has not read RTFM :-P