This only affects templates, and everything works fine if you translate a regular post or regular page without assigning a dynamic template?
Do you Coherence ES / Coherence EN / etc... When you are in the backend to make sure you are adding Spanish templates/pages where ES is shown?
Are you correctly linking the two languages together?
Are you creating one set of dynamic templates for Spanish, and a completely separate set for Basque?
This is a bit basic, just to make sure use are using the different language backends correctly - http://www.kriesi.at/support/topic/callout-translation-wpml#post-77814
Are you using 2 WPML plugins ( sitepress-multilingual-cms.2.6.0 , wpml-string-translation). please read more here, some other things I do troubleshooting WPML - http://www.kriesi.at/support/topic/ajax-portfolio-meta-fields-with-wpml#post-79635