Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 18978)
+++ wp-includes/functions.php	(working copy)
@@ -3840,7 +3840,7 @@
 	} else {
 		$cache_key = "{$wpdb->siteid}:$option";
 
-		if ( false !== get_site_option( $option ) )
+		if ( false !== get_site_option( $option, false, false ) )
 			return false;
 
 		$value = sanitize_option( $option, $value );
@@ -3921,7 +3921,8 @@
 function update_site_option( $option, $value ) {
 	global $wpdb;
 
-	$oldvalue = get_site_option( $option );
+	// Skip the cache
+	$oldvalue = get_site_option( $option, false, false );
 	$value = apply_filters( 'pre_update_site_option_' . $option, $value, $oldvalue );
 
 	if ( $value === $oldvalue )