If there is anything a computer should be able to do, it's compute. Apparently however, Excel 2002 and Excel 2007 have trouble with this, most basic, task.
Office-watch.com details a bug involving the addition of numbers with two decimal places. Simply put, Excel generates the wrong total. It comes close to the right answer, but at this point, it really should get the exact, completely correct answer - and it doesn't. See Excel SUM anomaly from April 29, 2008.
You may also want to verify that your copy of Excel has the necessary fix for another calculation … Read more