diff --git a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
index b459b64..50fa82d 100644
--- a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
+++ b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
@@ -300,18 +300,14 @@
 		supplier = ''
 		if d.purchase_order and not d.purchase_order in self.po_list:
 			supplier = sql("select supplier from `tabPurchase Order` where name = '%s'" % d.purchase_order)[0][0]
-			doctype = 'purchase order'
-			doctype_no = cstr(d.purchase_order)
 			if supplier and not cstr(self.doc.supplier) == cstr(supplier):
-				msgprint("Supplier name %s do not match with supplier name	of %s %s." %(self.doc.supplier,doctype,doctype_no))
+				msgprint("Supplier name %s do not match with supplier name	of purhase order: %s." %(self.doc.supplier,cstr(d.purchase_order)))
 				raise Exception , " Validation Error "
 
 		if d.purchase_receipt and not d.purchase_receipt in self.pr_list:
 			supplier = sql("select supplier from `tabPurchase Receipt` where name = '%s'" % d.purchase_receipt)[0][0]
-			doctype = 'purchase receipt'
-			doctype_no = cstr(d.purchase_receipt)
 			if supplier and not cstr(self.doc.supplier) == cstr(supplier):
-				msgprint("Supplier name %s do not match with supplier name	of %s %s." %(self.doc.supplier,doctype,doctype_no))
+				msgprint("Supplier name %s do not match with supplier name	of %s %s." %(self.doc.supplier,cstr(d.purchase_receipt)))
 				raise Exception , " Validation Error "
 
 	# Validate values with reference document
@@ -325,7 +321,7 @@
 	def validate_po_pr(self, d):
 		# check po / pr for qty and rates and currency and conversion rate
 
-		# always import_rate must be equal to import_rate of purchase order
+		# currency, import_rate must be equal to currency, import_rate of purchase order
 		if d.purchase_order and not d.purchase_order in self.po_list:
 			# currency
 			currency = cstr(sql("select currency from `tabPurchase Order` where name = '%s'" % d.purchase_order)[0][0])
@@ -334,7 +330,7 @@
 				raise Exception
 			# import_rate
 			rate = flt(sql('select import_rate from `tabPurchase Order Item` where item_code=%s and parent=%s and name = %s', (d.item_code, d.purchase_order, d.po_detail))[0][0])
-			if abs(rate - flt(d.import_rate)) > 1:
+			if abs(rate - flt(d.import_rate)) > 1 and cint(get_defaults('maintain_same_rate')):
 				msgprint("Import Rate for %s in the Purchase Order is %s. Rate must be same as Purchase Order Rate" % (d.item_code,rate))
 				raise Exception
 									
diff --git a/erpnext/patches/may_2012/same_purchase_rate_patch.py b/erpnext/patches/may_2012/same_purchase_rate_patch.py
new file mode 100644
index 0000000..44c0b3f
--- /dev/null
+++ b/erpnext/patches/may_2012/same_purchase_rate_patch.py
@@ -0,0 +1,7 @@
+def execute():
+	import webnotes
+	gd = webnotes.model.code.get_obj('Global Defaults')
+	gd.doc.maintain_same_rate = 1
+	gd.doc.save()
+	gd.on_update()
+	
\ No newline at end of file
diff --git a/erpnext/patches/patch_list.py b/erpnext/patches/patch_list.py
index d1df7de..32149d5 100644
--- a/erpnext/patches/patch_list.py
+++ b/erpnext/patches/patch_list.py
@@ -372,5 +372,9 @@
 		'patch_file': 'clear_session_cache',
 		'description': 'clears session cache as shifting to json format'
 	},
-
+	{
+		'patch_module': 'patches.may_2012',
+		'patch_file': 'same_purchase_rate_patch',
+		'description': 'Main same rate throughout pur cycle: in global defaults, by default set true'
+	},
 ]
\ No newline at end of file
diff --git a/erpnext/setup/doctype/global_defaults/global_defaults.py b/erpnext/setup/doctype/global_defaults/global_defaults.py
index 0427640..9d30885 100644
--- a/erpnext/setup/doctype/global_defaults/global_defaults.py
+++ b/erpnext/setup/doctype/global_defaults/global_defaults.py
@@ -35,7 +35,8 @@
 	'date_format': 'date_format',
 	'currency_format':'default_currency_format',
 	'account_url':'account_url',
-	'allow_negative_stock' : 'allow_negative_stock'
+	'allow_negative_stock' : 'allow_negative_stock',
+	'maintain_same_rate' : 'maintain_same_rate'
 }
 
 class DocType:
diff --git a/erpnext/setup/doctype/global_defaults/global_defaults.txt b/erpnext/setup/doctype/global_defaults/global_defaults.txt
index 5355c10..d1175b7 100644
--- a/erpnext/setup/doctype/global_defaults/global_defaults.txt
+++ b/erpnext/setup/doctype/global_defaults/global_defaults.txt
@@ -3,9 +3,9 @@
 
 	# These values are common in all dictionaries
 	{
-		'creation': '2012-04-18 17:00:50',
+		'creation': '2012-04-20 14:02:53',
 		'docstatus': 0,
-		'modified': '2012-04-19 17:24:45',
+		'modified': '2012-05-22 14:11:21',
 		'modified_by': u'Administrator',
 		'owner': u'Administrator'
 	},
@@ -224,8 +224,8 @@
 		'fieldtype': u'Select',
 		'label': u'Default Valuation Method',
 		'options': u'FIFO\nMoving Average'
-	},	
-	
+	},
+
 	# DocField
 	{
 		'colour': u'White:FFF',
@@ -511,6 +511,14 @@
 	# DocField
 	{
 		'doctype': u'DocField',
+		'fieldname': u'maintain_same_rate',
+		'fieldtype': u'Check',
+		'label': u'Maintain same rate throughout purchase cycle'
+	},
+
+	# DocField
+	{
+		'doctype': u'DocField',
 		'fieldname': u'hr',
 		'fieldtype': u'Section Break',
 		'label': u'HR',
@@ -543,4 +551,4 @@
 		'fieldtype': u'Data',
 		'label': u'SMS Sender Name'
 	}
-]
+]
\ No newline at end of file