Sorry for the delay, I got Joomla from Joomla! The CMS Trusted By Millions for their Websites
(last version 3.2.3), installed, and I was testing accurately that any change would cause errors again (like change the menu or activate the multilenguage modules and plugins).
And after that I can say that any error has appeared.
So looks as you said that was the Joomla version setup (spanish file) what cause the error, is it?
I really appreciate you help, it was really quickly, I am very happy you get the solution.