Rounding Errors

We're having issues with rounding on our cart, is there a patch or hot fix out there to address this bug?

Would you be more specific?
Is it related to Tax?
You ca try setting  shoppingcartsettings.roundpricesduringcalculation to false

Have you tried this from the following?
https://www.nopcommerce.com/en/boards/topic/52066/tax-rounding-to-the-third-decimal