diff --git a/addons/event_sale/models/sale_order.py b/addons/event_sale/models/sale_order.py
index 2d8b38d1987..8c2b8bc0c3f 100644
--- a/addons/event_sale/models/sale_order.py
+++ b/addons/event_sale/models/sale_order.py
@@ -30,8 +30,8 @@ class sale_order_line(osv.osv):
             help="Choose an event ticket and it will automatically create a registration for this event ticket."),
         # those 2 fields are used for dynamic domains and filled by onchange
         # TDE: really necessary ? ...
-        'event_type_id': fields.related('product_id', 'event_type_id', type='many2one', relation="event.type", string="Event Type"),
-        'event_ok': fields.related('product_id', 'event_ok', string='event_ok', type='boolean'),
+        'event_type_id': fields.related('product_id', 'event_type_id', type='many2one', relation="event.type", string="Event Type", readonly=True),
+        'event_ok': fields.related('product_id', 'event_ok', string='event_ok', type='boolean', readonly=True),
     }
 
     def _prepare_order_line_invoice_line(self, cr, uid, line, account_id=False, context=None):
diff --git a/addons/event_sale/views/sale_order.xml b/addons/event_sale/views/sale_order.xml
index 53fd9706eb4..7a1371de035 100644
--- a/addons/event_sale/views/sale_order.xml
+++ b/addons/event_sale/views/sale_order.xml
@@ -6,13 +6,17 @@
              <field name="model">sale.order</field>
              <field name="inherit_id" ref="sale.view_order_form" />
              <field name="arch" type="xml">
-                <xpath expr="//field[@name='product_id']" position="after">
+                <xpath expr="//field[@name='order_line']//form//field[@name='product_id']" position="after">
                     <field name="event_id" domain="['|', ('event_type_id','=', False),('event_type_id', '=', event_type_id),('date_end','&gt;=',time.strftime('%Y-%m-%d 00:00:00'))]" attrs="{'invisible': [('event_ok', '=', False)],'required': [('event_ok', '!=', False)]}"/>
                     <field name="event_ticket_id" domain="[('event_id', '=', event_id), ('seats_available', '>', 0)]" attrs="{'invisible': [('event_id', '=', False)], 'required': [('event_id', '!=', False)]}"
                         on_change="onchange_event_ticket_id(event_ticket_id, context)"/>
                     <field name="event_type_id" invisible="1"/>
                     <field name="event_ok" invisible="1"/>
                 </xpath>
+                <xpath expr="//field[@name='order_line']//tree//field[@name='product_id']" position="after">
+                    <field name="event_type_id" invisible="1"/>
+                    <field name="event_ok" invisible="1"/>
+                </xpath>
              </field>
         </record>