How to change decimal point on VAT calculation?

Hi, how can I change the number of decimal points on VAT? I have just noticed recently that Manager is out by 2 cents on Vat calculations.
e.g. Order value 1974.75. Vat @15% = 296.21. Manager calculates 296.23.
Any help or a workaround would be appreciated.
Manager version 18.7.85

VAT is calculated on a invoice line by line basis, not on the total of the invoice. If you check you will find that the calculation is correct.

Also you should update your version - the latest version is 18.9.14, so you are many versions behind