Index: users.php
===================================================================
--- users.php	(revision 22355)
+++ users.php	(working copy)
@@ -97,7 +97,8 @@
 			check_admin_referer( 'deleteuser' );
 
 			$id = intval( $_GET['id'] );
-			if ( $id != '0' && $id != '1' ) {
+			$user = get_userdata( $id );
+			if ( ! is_super_admin( $id ) || ( $user->user_email != get_site_option( 'admin_email' ) && get_current_user_id() != $id ) ) {
 				$_POST['allusers'] = array( $id ); // confirm_delete_users() can only handle with arrays
 				$title = __( 'Users' );
 				$parent_file = 'users.php';