Found this bug in PS 1.7.5.2 & PS 1.7.6.0:
Related to the post. No mail templates in the new language installed.
If anyone in the future will have this problem with the translation emails, after the translation is made automatically by prestashop, they can find them in << translations >> folder in the << root >> folder in form of a zip file. unzip and copy the core txt and html files in your theme folder in mails. the second folder will have the modules you have installed or by default on ps. copy them and paste them in there folders in your wanted translation folder. if the translation folder not exists, make it (ex: fr / ex: de) . after you do this, go to root/controllers/admin/ and look for AdminTranslationsController.php Open the file and find << function redirect($save_and_stay >> in the second elseif, were is ($save_and_stay) change '&theme=' with '&selected-theme='; and save the file. The save is global on the files that are opened and it will stay on page and you will now have all the translations for the new language for the emails, newsletters and so on.