diff --git a/accounts/doctype/sales_invoice/sales_invoice.py b/accounts/doctype/sales_invoice/sales_invoice.py
index ebc6dd3..486bc0a 100644
--- a/accounts/doctype/sales_invoice/sales_invoice.py
+++ b/accounts/doctype/sales_invoice/sales_invoice.py
@@ -322,8 +322,9 @@
 
 	
 	def pull_project_customer(self):
-		res = webnotes.conn.sql("select customer from `tabProject` where name = '%s'"%self.doc.project_name)
-		if res:
+		res = webnotes.conn.sql("select customer from `tabProject` where name = '%s'" %
+		 	self.doc.project_name)
+		if res and res[0][0]:
 			get_obj('DocType Mapper', 'Project-Sales Invoice').dt_map('Project', 'Sales Invoice', self.doc.project_name, self.doc, self.doclist, "[['Project', 'Sales Invoice']]")
 
 	def get_company_abbr(self):
diff --git a/patches/december_2012/clear_web_cache.py b/patches/december_2012/clear_web_cache.py
new file mode 100644
index 0000000..da71492
--- /dev/null
+++ b/patches/december_2012/clear_web_cache.py
@@ -0,0 +1,8 @@
+import webnotes
+def execute():
+	# build wn-web.js and wn-web.css
+	from website.helpers.make_web_include_files import make
+	make()
+
+	import website.utils
+	website.utils.clear_cache()
\ No newline at end of file
diff --git a/patches/patch_list.py b/patches/patch_list.py
index 2e8fc5e..90f908e 100644
--- a/patches/patch_list.py
+++ b/patches/patch_list.py
@@ -741,4 +741,8 @@
 		'patch_module': 'patches.december_2012',
 		'patch_file': 'replace_createlocal',
 	},
+	{
+		'patch_module': 'patches.december_2012',
+		'patch_file': 'clear_web_cache',
+	},
 ]
\ No newline at end of file
diff --git a/selling/doctype/sales_order/sales_order.py b/selling/doctype/sales_order/sales_order.py
index 9d23565..f024efc 100644
--- a/selling/doctype/sales_order/sales_order.py
+++ b/selling/doctype/sales_order/sales_order.py
@@ -59,7 +59,7 @@
 	#-------------------------
 	def pull_project_customer(self):
 		res = sql("select customer from `tabProject` where name = '%s'"%self.doc.project_name)
-		if res:
+		if res and res[0][0]:
 			get_obj('DocType Mapper', 'Project-Sales Order').dt_map('Project', 'Sales Order', self.doc.project_name, self.doc, self.doclist, "[['Project', 'Sales Order']]")
 			
 	
diff --git a/stock/doctype/delivery_note/delivery_note.py b/stock/doctype/delivery_note/delivery_note.py
index ece9936..ef22437 100644
--- a/stock/doctype/delivery_note/delivery_note.py
+++ b/stock/doctype/delivery_note/delivery_note.py
@@ -80,8 +80,8 @@
 
 
 	def pull_project_customer(self):
-		res = sql("select customer from `tabProject` where name = '%s'"%self.doc.project_name)
-		if res:
+		res = sql("select customer from `tabProject` where name = '%s'" % self.doc.project_name)
+		if res and res[0][0]:
 			get_obj('DocType Mapper', 'Project-Delivery Note').dt_map('Project', 'Delivery Note', self.doc.project_name, self.doc, self.doclist, "[['Project', 'Delivery Note']]")