Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 18436)
+++ wp-includes/taxonomy.php	(working copy)
@@ -656,14 +656,11 @@
 				}
 
 				$terms = implode( ',', $terms );
-
-				$alias = $i ? 'tt' . $i : $wpdb->term_relationships;
-
-				$join .= " INNER JOIN $wpdb->term_relationships";
-				$join .= $i ? " AS $alias" : '';
-				$join .= " ON ($primary_table.$primary_id_column = $alias.object_id)";
-
-				$where[] = "$alias.term_taxonomy_id $operator ($terms)";
+				
+				if( ! $i )
+					$join = " INNER JOIN $wpdb->term_relationships ON ($primary_table.$primary_id_column = $wpdb->term_relationships.object_id)";
+				
+				$where[] = "$wpdb->term_relationships.term_taxonomy_id $operator ($terms)";
 			} elseif ( 'NOT IN' == $operator ) {
 
 				if ( empty( $terms ) )