This one should work? postinfo.php line 48, replace
PHP Code:
$author_url = get_author_posts_url($post_author_id, $author_name);
with
PHP Code:
$author_url = get_author_posts_url($post_author_id);
and leave / change back line 50 to how it was before:
PHP Code:
$author_linked = '<a href="' . $author_url . '">' . $author_name . '</a>';
On the resulting page there might be something like "Archive for '' Category"... looking into that now