No I'm running 2.0.1-rc1 - I think it is my own code:
<?php
if(get_query_var('author_name')) :
$curauth = get_userdatabylogin(get_query_var('author_name'));
else :
$curauth = get_userdata(get_query_var('author'));
endif;
?>
But I may be wrong. Just wondered if anything WP I call here had changed.
Thanks anyway Sean