[Plugin: Co-Authors Plus] Tweaking my theme for coauthors

Hi to all!
I’m trying to use this coauthor plugin into my template, it’s mystique (http://digitalnature.ro/projects/mystique).
First of all, i declare I’m neither a web programmer, nor a general coder 😀
It has this function to display teh author:

<?php printf(__('Posted by %1$s in %2$s','mystique'),'<a href="'. get_author_posts_url(get_the_author_ID()) .'" title="'. sprintf(__("Posts by %s","mystique"), attribute_escape(get_the_author())).' ">'. get_the_author() .'</a>',$category_link);

it writes on the page something like “Published by admin in uneuseful category “
How you can see there’s no a clean the_author() call; I tried some “combinations” of coahthors functions but the best I achieved was like: “admin1 and admin2published by in unuseful category”.

Someone could help me?
My blog url (under construction) ishttp://spingitoridicavalieri.webatu.com, the first article (Ciao mondo!!” is coauthor-ed.

Bye!

http://wordpress.org/extend/plugins/co-authors-plus/