Comment 1 for bug 805697

I think the issue is that in anglo-saxon invoice.py line 122 the price variance calculation is based on the average cost at the time the invoice is processed, not the original PO cost.

So either,

a) this needs to be changed to pick up the original PO cost to calculate the variance; or
b) when the goods are receipted, if there is a difference to the average cost there will need to be a GL entry created for that difference.

My preference is a) so that in reconciling the goods received not invoiced account in the GL there is a recognisable recognition between PO and invoice (ie any difference is solely price variance an invoice processing time)