Fix for 2.1.1 with wrong author info being pulled on author pages

coauthors-plus-author-page-fix.php

<?php
/**
 * Fix for author info not properly displaying on author pages
 *
 * On an author archive, if the first story has coauthors and
 * the first author is NOT the same as the author for the archive,
 * the query_var is changed.
 *
 */
function coa_fix_author_page( &$post ) {

	if( is_author() ) {
		global $wp_query, $authordata;

		// Get the id of the author whose page we're on
		$author_id = $wp_query->get( 'author' );

		// Check that the the author matches the first author of the first post
		if( $author_id != $authordata->ID ) {
			// The IDs don't match, so we need to force the $authordata to the one we want		
			$authordata = get_userdata( $author_id );
		}
	}
}
// Fix for author info not properly displaying on author pages
add_action( 'the_post', 'coa_fix_author_page' );