But there the description also included the boilerplate "This update is recommended for all users running Mac OS X 10.6.8" so cautious types would have been pulled in two directions: should I take Apple's advice and apply this update even though it provides no obvious benefit and might possibly adversely affect the smooth running of my system?
Now some users have worked out what Apple didn't tell us about the update and why it is so important.
The Software Installer as supplied with Snow Leopard checks the security certificate within installer packages, and the certificate Apple attached to a wide range of updates and software installers expired this month. Consequently, the original Software Installer refuses to install them.
So if you need to reinstall Snow Leopard from DVD, you won't be able to bring it (more or less) up to date by using the copy of the 10.6.8 combo updater that you downloaded more than a few weeks ago. Instead, you'll need to download a fresh copy of the 10.6.8 updater, either from Apple's web site or via Software Update.
Page 2: problems and solutions
The problem apparently extends to applications, with the iLife '11 DVD reportedly being affected. But that's no big deal for most users, as they can simply apply the Software Installer update and then proceed.
Life's more complicated if you manage a fleet of Macs using an automated software distribution mechanism. So Greg Neagle, a Mac administrator in an enterprise environment, has created a python script to help remove certificates from packages.
But wasn't the whole point of attaching certificates to packages to improve security? That is, the certificate provides assurance that the package really came from Apple and hasn't been tampered with. If that was a good idea, why is it suddenly a good idea to ignore expired certificates?
Or is the problem simply that Apple used a certificate that expired far too soon?