Comment 4 for bug 897319

In ~openerp/openobject-addons/6.0
Report don't use price_subtotal of invoice_line

 /account/report/account_invoice_report.py (revision 5099)
                    sum(case when ai.type in ('out_refund','in_invoice') then
                         ail.quantity*ail.price_unit * -1
                        else
                         ail.quantity*ail.price_unit
                        end) / cr.rate as price_total,

~openerp/openobject-addons/6.1 : /account/report/account_invoice_report.py (revision 6639)
                    sum(case when ai.type in ('out_refund','in_invoice') then
                         -ail.price_subtotal
                        else
                          ail.price_subtotal
                        end) / cr.rate as price_total,