=== modified file 'addons/mrp/mrp_view.xml'
--- old/addons/mrp/mrp_view.xml	2011-02-09 19:22:24 +0000
+++ new/addons/mrp/mrp_view.xml	2013-01-16 22:22:00 +0000
@@ -230,7 +230,7 @@
             <field name="type">form</field>
             <field name="arch" type="xml">
                 <form string="Bill of Material">
-                    <field name="product_id" on_change="onchange_product_id(product_id, name)" select="1"/>
+                    <field name="product_id" on_change="onchange_product_id(product_id, name)" select="1" domain="[('id','!=', parent.product_id)]"/>
                     <newline/>
                     <field name="product_uom"/>
                     <field name="product_qty"/>