From CIO.com…

Buggy Microsoft Excel Patch Causes Bad Math

If you installed one of those Excel security patches issued by Microsoft earlier this week, you may want to double-check your math.

That’s because a bug in the recent MS08-014 patch is causing Excel to return zeroes instead of the correct number when certain types of macros are run within the program.

The issue, which does not affect all Excel users, messes up calculations for Office Excel 2003 users who are grabbing data such as stock quotes or inventory levels from sources in real time and plugging them into an Excel array.