updated 08:00 pm EST, Fri February 3, 2012
Available via Software Update for 10.6.8 users
A problem with the previous 2012-001 Security Update posted for users of Snow Leopard (client and server) that caused Rosetta-based apps to misbehave or fail entirely has been corrected, and the company is pushing a "v1.1" edition of the update through its Software Update servers (support web page not yet updated). Over the next 24 hours, users who installed the previous security patch for 10.6.8 systems should see the update available.
The issue with Rosetta began appearing yesterday, particularly with users of older versions of Microsoft Office (such as the 2004 and v.X editions) reporting that the app either wouldn't launch or wouldn't save documents under Snow Leopard. As other reports emerged, it became obvious that something in the security update had "broken" a vital part of Rosetta, which is a technology optionally available for Snow Leopard that allows it to run PowerPC-based older apps.
Rosetta is not present in Lion, so the fixes (which were rolled into the 10.7.3 update) did not cause issues for Lion users. Users who never installed the optional Rosetta component are likewise unaffected by the error.
According to release notes from the v1.1 update, the problem was traced back to some ImageIO security fixes, which the new version corrects. The fixes for ImageIO in the original release focused on mishandling of certain kinds of TIFF image files and updated a library called libpng to remove security concerns dealing with PNG images.
Snow Leopard uses should look for the v1.1 edition of Security Update 2012-001 to appear shortly. The update restores Rosetta to its working state and also contains many other important security updates and is recommended for 10.6.8 users. Apple's support downloads web page will soon be updated with a standalone version.