Microsoft tech support folks say a patch released last week to fix security vulnerabilities in Excel 2003 causes the spreadsheet to multiply things incorrectly.The error shows up if a patched version of Excel is linked to a real-time data source through macros built with Visual Basic for Applications, according to Microsoft.

The patch, known as MS08-014, was released for Excel 2003 Service Packs 2 and 3.

Microsoft said that the company has issued a new patch — to patch last week’s patch. They’ve patched the patch!

If you’re not running Excel 2003, this release doesn’t apply to you and you don’t need to be concerned about the patched patch.

The original patch was designed to plug a security hole that could allow remote code execution if users open Excel in certain ways -possibly allowing an attacker to gain control over affected systems.

This is just the latest in a long line of Excel-related math problems. Last year Microsoft issued a patch for Excel 2007 for a problem that caused Excel 2007 to produce significant multiplication errors. That flaw occurred during calculations that would ordinarily result in, or be close to, the number 65,535. Instead, Excel 2007 would produce a result of 100,000.

It isn’t just Microsoft and Excel that have math issues from time to time. Does anyone remember the Pentium FDIV recall from 1983?

We’re just glad they usually get fixed pretty quickly!