I modified the contenido.tpl but when i try to view a node with class=16 (contenido), it shows me the old contenido.tpl. That changes was made using the eZP web admin.
It seems a cache problem but... i cleared it 1837632 times (aprox. :D).
I disabled ALL caches and now all works. I can't undertstand why the cache don't works how it must works. I will develop my website with all caches disabled. I will try to solve the cache related problems when the website is completed.