help with ñ and vocals accent in spanish website...

Dear friends need your help
In my website installed the black and white template but
The articles and menu Joomla doesnt work correctly, but just in JOOMLA articles and menu, because in the K2 items this work correctly and I can see text with ñ or accent in vocals...

This spanish website client dont work with ñ or vocals accent (á é í ó ú)
when I write an article like this:

"querida señorita..."

after saving the articles shows:

"querida se


Please need to know why, what is the problem, how can I fix it?

Thank you!