I installed the Tax Exempt 2.1 module, and it works perfectly.

EXCEPT -- it appears to calculate sales tax to three decimal places, then rounds up to two decimal places. ZenCart, on the other hand, is only using two decimal places and doesn't seem to be doing any rounding (at least that's what's happening with my current configuration -- I'm using version 1.3.7). As a result, the tax exempt amount is sometimes one penny more than the tax amount, which means my client is out a penny for every tax-exempt customer he gets (and he gets a lot).

Is there some way to either make the module calculate tax to two decimal places, OR make ZenCart calculate tax to three decimal places? Either solution is fine with my client. Thanks!