Recently on one of the sites running Drupal 7 I enabled comments on a page and noticed, that the 'Comment' label needs to be translated but this could not be done using the translation interface, that's located in Drupal's Settings.
But there is a way to translate the 'Comment' label, although it may be a bit harder to find.
Steps to Translate the 'Comment' label
1. Go to content types page (admin/structure/types/manage/sekcija-revizorjev-is/comment/fields) and there's a list of all fields used by this content type.
2. One of the fields is named 'Comment'.
3. Click on 'Edit' on the right in the table.
4. Change the name from the default 'Comment' to what you want it to be.