Actual sales tax amount

Hi there,

I have a abnormal situation. I am on the AX2012 CU7.

I have a back dated GL journal USD transaction with sales tax while my base currency is MYR.

After the record created, I changed the exchange rate, when I check the amount in base currency, the input amount and tax amount base on the new exchange rate.

However if I amended the tax value in “Actual sales tax amount”, the base currency transaction amount will still base on the amended exchange rate, but the base currency tax amount doesn’t it is based on the back dated rate.

The example below transacted on 15/10/2015 while today is 20/10/2015

Journal Exhange rate 4.295

Debit amount USD6.00 and after converted is MYR25.77

Tax amount(6%) USD0.36 and after converted is MYR1.55

If I amended the “Actual sales tax amount” to USD0.38, the result of system show below

Journal Exhange rate 4.295

Debit amount USD6.00 and after converted is MYR25.77

Tax amount(6%) USD0.36

Actual sales tax amount USD0.38 and after converted is MYR1.59

System give the result MYR1.63 because system takes the exchange rate on 15/10/2015 4.195.

Please advise is there a setting or any other cause for system behave like this?

Regards,

Dan