Snow Leopard 'burps'
Euan Williams
Although the reported issues affecting some users with the latest Lion updater to 10.7.3 can be successfully avoided by downloading the Combo updater, (see: Lion Burps) it seems that Rosetta has sometimes been disabled in the 10.6.8 Snow Leopard security update.Advice at the moment is to stick with 10.6.7 if you need Rosetta to run old PowerPC apps.
http://reviews.cnet.com/8301-13727_7-57370890-263/rosetta-broken-in-os-x-10.6.8-after-security-update/?tag=nl.e795