[SL] Rounding Error or Human Error?

[Luke <sl...@li...>]

Hello

I have an invoice which appears to be calculating the discount 
incorrectly.

The line item cost is $2.95 (sellprice--the list price is $2.99, and I 
lowered this on the invoice to compensate for another seeming error).

Setting the discount to 10, with a quantity of 12, yealds a cost of 
$31.80, while my calculater seems to think that it should equal $31.86.

SL 2.8.10; PGSQL 8.2.

Am I missing something obvious here?

Luke