Site Map Menu are not translatable
Be aware of the Main Menu not translated issue, which states:


  When using the default 'Main menu' menu, and outputting that on the sitemap, the title, or menu name, isn't translated ...


I just double checked in a multi language site also where I have the i18n Menu Translation sub-module enabled (one of the Internationalization sub-modules).

I tried editing the Sitemap menu item to be translated, by navigating to admin/structure/menu/manage/navigation. From there I tried to use the "translate" link (for the Sitemap menu item), which one would expect that it can be used to translate that menu item. 

However, after doing so, I only get something like "You are not authorized to access this page."

This issue appears to be fixed in the most recent dev version.