I18n translation of site_name not working
To translate a Drupal 7 Site name you have to activate Variable translation module (which is in the same package as i18n) and the required ones (like Variable store). 

After you install these modules, go to Configuration -&gt; Multilingual settings -&gt; Variables tab and choose Site name (?q=admin/config/regional/i18n/variable),Then go to Configuration -&gt; System -&gt; Site information (q=admin/config/system/site-information) and select the language you want. Change the Site name field and save.

You'll find the translated site name in variable_store table.