Hi, today I've find lot of warning s on webmaster tools, all those warning are about duplicate titles and duplicate descriptions, all coming from pages with same language, but different countries.
just to make an example I have the same page in different languages/locales:
the english and canadian versions gave me that warning. because the language is the same, of course, but the URL is different.
The solution could be to insert the hreflang meta link in the top of the pages.
You can find some informations about it here.
I have coded a little module for Prestashop 1.6 to handle the creation of hreflang meta links. Feel free to use and modify it, and of course any donation (or at least a click on banners) are appreciated.