Header media title and Polylang

Just bought Fullscreen Pro. Your webpage says "Glance over our Multilingual WordPress themes with built-in multilingual support. Supports plugin like WPML, Polylang and qTranslate." I'm using Polylang (WPML-compatibility enabled), but cannot figure out how to translate the Header Media Title or Header Media Text. It does not show up in the Textstring-translations, nor anywhere else. What to do?