Property Manager - Amount rounding

Hello,

Property Manager is inconsistent with the way rent increase is calculated and this is causing a problem with some customers, who have been used to receiving invoices at a certain value. I have investigated a lease and find that the rent increase is calculated on the prior period monthly/quarterly value to 3 decimal places but when this is converted to the annual value, it is calculated on the current months value to two decimal places. There is not a huge difference (pennies) but it is enough to cause problems with tricky customers.

I would like to know if there is a quick and easy fix to bring this in line.