I was thinking about that, I think it was the cache ... After I set the joomla editor I didn't clean the cache and I didn't seen the editor functioning on editing the content of the section.
P.S. did you remarked when you login first time in the frontend you got a 500 error ? Or a blank white page ? ... The site loads corect after refresh .... This is not releated with this topic but, just to confirm other issue ....