when generating feed (in my case with url like: /feed.php?ns=blog), author's name is not translated to the real name.
I think it's because Auth object is not visible in following function at proper rows, when it's used.
rss_builditems()
http://dev.splitbrain.org/reference/dokuwiki/nav.html?feed.php.html#rss_builditems
so i fixed it with
global $auth;
at the beginning of the function.