Charges on a Purchase Order - AX 2012

Hi

We have Financial charges that we include on a purchase order, eg commission.

Our purchase order is in USD but the charges are in NZD. There is some rounding differences happening in the charges, where the Amount in Transaction Currency is NZD 1040.00, and the amount in the Amount Column is NZD 1040.03. The $0.03 is then getting posted to GST, when it should not as the GST total is $0.

Journal number Voucher Date Year closed Ledger account Currency Amount in transaction currency Amount Amount in reporting currency Posting layer
GLJT002944 PI000049 30/08/2013 No Z5014 NZD -1040.00 -1040.03 -1040.03 Current
GLJT002944 PI000049 30/08/2013 No Z1521 USD 0.00 -0.03 -0.03 Current
GLJT002944 PI000049 30/08/2013 No Z3255 NZD 1040.00 1040.03 1040.03 Current

Is there a rounding that I need to adjust somewhere?

Any ideas on how to fix this?

Thanks in advance