Index: wp-includes/template-functions-author.php
===================================================================
--- wp-includes/template-functions-author.php	(revision 3000)
+++ wp-includes/template-functions-author.php	(working copy)
@@ -179,9 +179,20 @@
 	$query = "SELECT ID, user_nicename from $wpdb->users " . ($exclude_admin ? "WHERE user_login <> 'admin' " : '') . "ORDER BY display_name";
 	$authors = $wpdb->get_results($query);
 
+	$query = "SELECT DISTINCT post_author AS author,
+		COUNT(ID) AS count
+		FROM $wpdb->posts
+		WHERE post_status = 'publish'
+		AND post_date_gmt <'".current_time('mysql','1')."'
+		GROUP BY post_author";
+	$author_count = array();
+	foreach ( $wpdb->get_results($query, ARRAY_A) as $row ) {
+		$author_count["{$row['author']}"] = $row['count'];
+	}
+
 	foreach ( $authors as $author ) {
 		$author = get_userdata( $author->ID );
-		$posts = get_usernumposts($author->ID);
+		$posts = isset($author_count["{$author->ID}"]) ? $author_count["{$author->ID}"] : "0";
 		$name = $author->nickname;
 
 		if ( $show_fullname && ($author->first_name != '' && $author->last_name != '') )
@@ -231,4 +242,4 @@
 	}
 }
 
-?>
\ No newline at end of file
+?>