replace in line 312 (version 1 of plugin)
update_post_meta($newPost, $this->_post_meta_Submitter, htmlentities(($authorName)));
to
update_post_meta($newPost, $this->_post_meta_Submitter, htmlentities($authorName, ENT_QUOTES, "UTF-8"));
this helped me with russian characters, this is because the function htmlentities default encoding is ISO-8859-1