diff --git a/patches/march_2013/p07_update_valuation_rate.py b/patches/march_2013/p07_update_valuation_rate.py
index 885fad6..eaeeac1 100644
--- a/patches/march_2013/p07_update_valuation_rate.py
+++ b/patches/march_2013/p07_update_valuation_rate.py
@@ -2,13 +2,18 @@
 
 def execute():
 	webnotes.reload_doc("accounts", "doctype", "purchase_invoice_item")
-	
+	webnotes.conn.auto_commit_on_many_writes = True
 	for purchase_invoice in webnotes.conn.sql_list("""select distinct parent 
 		from `tabPurchase Invoice Item` where docstatus = 1 and ifnull(valuation_rate, 0)=0"""):
 		pi = webnotes.get_obj("Purchase Invoice", purchase_invoice)
-		pi.calculate_taxes_and_totals()
+		try:
+			pi.calculate_taxes_and_totals()
+		except:
+			pass
 		pi.update_raw_material_cost()
 		pi.update_valuation_rate("entries")
 		for item in pi.doclist.get({"parentfield": "entries"}):
 			webnotes.conn.sql("""update `tabPurchase Invoice Item` set valuation_rate = %s 
 				where name = %s""", (item.valuation_rate, item.name))
+
+	webnotes.conn.auto_commit_on_many_writes = False
\ No newline at end of file