diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 4e6de6310cc..887cc9479a1 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -436,6 +436,14 @@ class stock_picking(osv.osv):
                 res.add(move.picking_id.id)
         return list(res)
 
+    def _get_pack_operation_exist(self, cr, uid, ids, field_name, arg, context=None):
+        res = {}
+        for pick in self.browse(cr, uid, ids, context=context):
+            res[pick.id] = False
+            if pick.pack_operation_ids:
+                res[pick.id] = True
+        return res
+
     _columns = {
         'name': fields.char('Reference', size=64, select=True, states={'done':[('readonly', True)], 'cancel':[('readonly',True)]}),
         'origin': fields.char('Source Document', size=64, states={'done':[('readonly', True)], 'cancel':[('readonly',True)]}, help="Reference of the document", select=True),
@@ -469,6 +477,7 @@ class stock_picking(osv.osv):
         'partner_id': fields.many2one('res.partner', 'Partner', states={'done':[('readonly', True)], 'cancel':[('readonly',True)]}),
         'company_id': fields.many2one('res.company', 'Company', required=True, select=True, states={'done':[('readonly', True)], 'cancel':[('readonly',True)]}),
         'pack_operation_ids': fields.one2many('stock.pack.operation', 'picking_id', string='Related Packing Operations'),
+        'pack_operation_exist': fields.function(_get_pack_operation_exist, type='boolean', string='Pack Operation Exists?', help='technical field for attrs in view'),
         'picking_type_id': fields.many2one('stock.picking.type', 'Picking Type', required=True),
 
         # Used to search on pickings
diff --git a/addons/stock/stock_view.xml b/addons/stock/stock_view.xml
index 25de91d6cd3..95cd2e49a1f 100644
--- a/addons/stock/stock_view.xml
+++ b/addons/stock/stock_view.xml
@@ -586,7 +586,7 @@
                     <button name="action_assign" states="confirmed" string="Check Availability" type="object" class="oe_highlight" groups="base.group_user"/>
                     <button name="force_assign" states="confirmed" string="Force Availability" type="object" class="oe_highlight" groups="base.group_user"/>
                     <button name="do_partial" states="assigned" string="Transfer Done" groups="stock.group_stock_user" type="object" class="oe_highlight"/>
-                    <button name="do_prepare_partial" states="assigned" string="Partial Transfer" groups="stock.group_stock_user" type="object" class="oe_highlight"/>
+                    <button name="do_prepare_partial" string="Partial Transfer" groups="stock.group_stock_user" type="object" class="oe_highlight" attrs="{'invisible': ['|',('pack_operation_exist', '=', True),('state','!=','assigned')]}"/>
                     <button name="%(act_stock_return_picking)d" string="Reverse Transfer" states="done" type="action" groups="base.group_user"/>
                     <button name="action_cancel" states="assigned,confirmed,draft" string="Cancel Transfer" groups="base.group_user" type="object"/>
                     <field name="state" widget="statusbar" statusbar_visible="draft,assigned,done" statusbar_colors='{"shipping_except":"red","invoice_except":"red","waiting_date":"blue"}'/>
@@ -608,8 +608,10 @@
                         </group>
                     </group>
                     <notebook>
-                        <page string="Partial/Packing Operations" attrs="{'invisible': [('pack_operation_ids','=',False)]}">
-                            <field name="pack_operation_ids">
+                        <page string="Products">
+                            <field name="pack_operation_exist" invisible="1"/>
+                            <button name="action_pack" string="Create Package" type="object" class="oe_link" attrs="{'invisible': ['|',('pack_operation_exist', '=', False),('state', 'not in', ('draft','assigned','confirmed'))]}"/>
+                            <field name="pack_operation_ids" attrs="{'invisible': [('pack_operation_exist', '=', False)]}">
                                 <tree editable="top">
                                     <field name="product_id"/>
                                     <field name="product_uom_id"/>
@@ -619,9 +621,6 @@
                                     <field name="result_package_id"/>
                                 </tree>
                             </field>
-                            <button name="action_pack" states="draft,assigned,confirmed" string="Create Package" type="object" class="oe_link"/>
-                        </page>
-                        <page string="Products">
                             <field name="move_lines" context="{'address_in_id': partner_id, 'form_view_ref':'view_move_picking_form', 'tree_view_ref':'view_move_picking_tree'}"/>
                             <field name="note" placeholder="Add an internal note..." class="oe_inline"/>
                         </page>
@@ -1490,16 +1489,12 @@
             </field>
         </record>
         
-        
-        
         <record model="ir.actions.act_window" id="quantsact">
             <field name="name">Quants</field>
             <field name="context">{'search_default_productgroup':'1'}</field>
             <field name="res_model">stock.quant</field>
         </record>
 
-
-
         <record model="ir.ui.view" id="view_stock_quant_form">
             <field name="name">stock.quant.form</field>
             <field name="model">stock.quant</field>