<openerp>
  <data>

    <record id="view_move_form_remove_button" model="ir.ui.view">
      <field name="name">account.move.form.remove.button</field>
      <field name="model">account.move</field>
      <field name="inherit_id" ref="account.view_move_form"/>
      <field name="arch" type="xml">
        <data>
          <button name="button_validate" position="replace"/>
          <button name="button_cancel" position="after">
            <field name="update_posted" invisible="1"/>
          </button>
          <button name="button_cancel" position="attributes">
            <attribute name="attrs">{'invisible': ['|', ('update_posted', '=', False)]}</attribute>
          </button>
        </data>
      </field>
    </record>

  </data>
</openerp>