diff --git a/addons/account/invoice.py b/addons/account/invoice.py
index 46e64570a14..bca5770accc 100644
--- a/addons/account/invoice.py
+++ b/addons/account/invoice.py
@@ -922,7 +922,7 @@ class account_invoice(osv.osv):
             invtype = obj_inv.type
             number = obj_inv.number
             move_id = obj_inv.move_id and obj_inv.move_id.id or False
-            reference = obj_inv.reference
+            reference = obj_inv.reference or ''
             if not number:
                 tmp_context = {
                     'fiscalyear_id': obj_inv.period_id.fiscalyear_id.id
diff --git a/addons/account/wizard/account_use_model_view.xml b/addons/account/wizard/account_use_model_view.xml
index 03ca451e509..71f026237ac 100644
--- a/addons/account/wizard/account_use_model_view.xml
+++ b/addons/account/wizard/account_use_model_view.xml
@@ -50,7 +50,7 @@
             <field name="type">form</field>
             <field name="arch" type="xml">
                 <form string="Use Model">
-                    <group colspan="4" col="6">
+                    <group colspan="4" col="6" width="300" height="70">
                            <label string = "Entry Lines Created." colspan="2"/>
                            <newline/>
                         <button icon="gtk-ok" special="cancel" string="Ok"/>
@@ -66,7 +66,7 @@
             <field name="type">form</field>
             <field name="arch" type="xml">
                 <form string="Use Model">
-                    <group colspan="4" col="6">
+                    <group colspan="4" col="6" width="300" height="70">
                            <label string = "Are you sure you want to create entries?" colspan="2"/>
                            <newline/>
                         <button icon="terp-gtk-stop" special="cancel" string="Cancel"/>