Hi,
The actual cost components transferred to CO-PA match the cummulative inventory value. Please make sure you compare this material ledger line to CO-PA value fields valuation.
You need to understand that the purpose fo the transfer is to allow creation of contribution P&L report in CO-PA that will be consistent with FI P&L. FI COGS correspond to the cummlative ML line.
For further details on the subject and much more, you can read my article on SAP Financials Experts:
Regards,
David