Product Price Manager & Sales Tax

Hello,

I have a new install of 1.3.9e. I have oceanfront template. No mods installed.

I would like to have Product Prices display as 3 decimal places. My issue is when I change to 3 decimals, sales tax also displays at checkout as 3 decimals which affects the total sale. Here is an example:

Subtotal - 42.000
UPS Ground - 10.990
SC Tax 6.0% - 3.179
Total - 56.169

I cannot get sales tax to round to 2 decimal places. I have set in My Store, tax decimal places to 2, 1 0, it makes no difference I keep getting the same as above example.

Anyone have an idea?:unsure:

Is there any particular reason why you need to use three decimal places.:dontgetit

Is there some rounding problem elsewhere that's causing you to try this solution?

My product prices are out to 3 decimal places. If I round up to 2 decimal places, my prices may not be competitive I am sorry to say.
Any idea why sales tax will not round to 2 decimals even after I set that in My store settings?
Thank you for helping!