Discount calculation not same in 4.10 as in 4.07 (free version)

[iCARS]

I recently updated my computer from Windows 7 to Windows 8.1. On Windows 7 I was using version 4.7, but this won't run on Windows 8 so I updated to 4.10 (the latest). in 4.07, the discount of 33.33% on $150 calculated to exactly $50, reducing the $150 to $100 which is what I wanted. On 4.10, 33.33% calculates to $49.99, reducing the $150 to $100.01. I've tried changing the discount to add a third decimal place, but EI rounds it to 2 decimal places, so I cannot see a way of getting the one-third discount to calculate correctly. Can anyone help?