Author Page – Not Working – Cache Problem ?

I have an author template that tries to display the author’s first name and lastname and the profile text.

<?php
if(get_query_var(‘author_name’)) :
$curauth = get_userdatabylogin(get_query_var(‘author_name’));
else :
$curauth = get_userdata(get_query_var(‘author’));
endif;

echo $curauth->first_name. ‘ ‘ . $curauth->last_name ;?>

?>

This code fails to get the firstname and the lastname.
I do not know why.
I am running WP 2.0.1