Index: wp-activate.php
===================================================================
--- wp-activate.php	(revision 13013)
+++ wp-activate.php	(working copy)
@@ -16,7 +16,10 @@
 if ( is_object( $wp_object_cache ) )
 	$wp_object_cache->cache_enabled = false;
 
-do_action("activate_header");
+function do_activate_header() {
+	do_action("activate_header");
+}
+add_action( 'wp_head', 'do_activate_header' );
 
 function wpmu_activate_stylesheet() {
 	?>