Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 12397)
+++ wp-includes/functions.php	(working copy)
@@ -600,7 +600,7 @@
 		wp_cache_set( 'notoptions', $notoptions, 'options' );
 	}
 
-	$wpdb->insert($wpdb->options, array('option_name' => $name, 'option_value' => $value, 'autoload' => $autoload) );
+	$wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE `option_name` = VALUES(`option_name`), `option_value` = VALUES(`option_value`), `autoload` = VALUES(`autoload`)", $name, $value, $autoload ) );
 
 	do_action( "add_option_{$name}", $name, $value );
 	do_action( 'added_option', $name, $value );