diff --git a/application/models/Sale.php b/application/models/Sale.php
index 4b639b147..a00586c50 100644
--- a/application/models/Sale.php
+++ b/application/models/Sale.php
@@ -45,17 +45,15 @@ class Sale extends CI_Model
 			$sale_total = "ROUND(SUM($sale_price), $decimals) + $sales_tax + $cash_adjustment";
 		}
 
-
-
 		// create a temporary table to contain all the sum of taxes per sale item
 		$this->db->query('CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->dbprefix('sales_items_taxes_temp') .
-			' (INDEX(sale_id), INDEX(item_id)) ENGINE=MEMORY
+			' (INDEX(sale_id, item_id, line)) ENGINE=MEMORY
 			(
 				SELECT sales_items_taxes.sale_id AS sale_id,
 					sales_items_taxes.item_id AS item_id,
 					sales_items_taxes.line AS line,
-					SUM(ROUND(CASE WHEN sales_items_taxes.tax_type = 0 THEN sales_items_taxes.item_tax_amount ELSE 0 END, ' . $decimals . ') AS internal_tax, 
-					SUM(ROUND(CASE WHEN sales_items_taxes.tax_type = 1 THEN sales_items_taxes.item_tax_amount ELSE 0 END), ' . $decimals . ' AS sales_tax
+					SUM(ROUND(CASE WHEN sales_items_taxes.tax_type = 0 THEN sales_items_taxes.item_tax_amount ELSE 0 END, ' . $decimals . ')) AS internal_tax, 
+					SUM(ROUND(CASE WHEN sales_items_taxes.tax_type = 1 THEN sales_items_taxes.item_tax_amount ELSE 0 END, ' . $decimals . ')) AS sales_tax
 				FROM ' . $this->db->dbprefix('sales_items_taxes') . ' AS sales_items_taxes
 				INNER JOIN ' . $this->db->dbprefix('sales') . ' AS sales
 					ON sales.sale_id = sales_items_taxes.sale_id