Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 17507)
+++ wp-includes/taxonomy.php	(working copy)
@@ -678,11 +678,13 @@
 
 				$terms = implode( ',', $terms );
 
-				$where[] = "$primary_table.$primary_id_column NOT IN (
-					SELECT object_id
-					FROM $wpdb->term_relationships
-					WHERE term_taxonomy_id IN ($terms)
-				)";
+				$alias = $i ? 'tt' . $i : $wpdb->term_relationships;
+
+				$join .= " LEFT JOIN $wpdb->term_relationships";
+				$join .= $i ? " AS $alias" : '';
+				$join .= " ON ($primary_table.$primary_id_column = $alias.object_id AND $alias.term_taxonomy_id IN ($terms))";
+
+				$where[] = "$alias.object_id IS NULL";
 			} elseif ( 'AND' == $operator ) {
 
 				if ( empty( $terms ) )