Rounding

Works well for me except for one thing:

I have in my cart 6 products at 9.95 each with a $20 coupon distributed over 6 products so it will divide $20 by 6 and put $3.33 on each product. The coupon will then add up to $3.33 x 6 = -$19.98

There's 2 cents missing. Not much I know but for customers every cent are important :-)