Encoding problem in Page 404

Hi all,

Already using a child theme, under which I’ve copied the 404 error page coming from the default theme. Edited the new 404 error page and translated some texts into Spanish. All seems correct, but when this page is shown, some strange characters are shown, seems an enconding problem, and it’s the unique page in which I’m having this abnormal behaviour.

My wordpress installation is originally in English, but then changed a parameter in wp-config to set it in Spanish, just in case this info also helps. And I’m having this econding problem just with this page, what should I change?

Check out this error in my blog.

Thanks and regards,
Miguel.