Settlement of production Variance to COPA-Two line items

I am settleing production variances to COPA using PA transfer structure which is assigned to order type. I have made corresponding assignment of variance categories & cost elements to propoer value field in COPA customizing. Variance is also calculated properly for the order.

However once I make the settlement of order, two line items are generated, 1)One for target cost with -ve sign and 2) another for actual cost incurred in the order. Accounting document is generated for only the first entry. The net effect in the COPA value field is correct & equal to the order variance. I wish to know is this a proper posting (i.e two seperate line item document to COPA) or this is due to some customizing error.

Thanks,

Joydeep