I missed this initially. I got a call yesterday from a client who couldn't save properly in Word 2004, and my suggestions didn't work. Today, while checking the Mac blogs I read the news that Apple screwed up the Security Update 2006-001 for Snow Leopard 10.6.8, causing Rosetta to fail. That caused problems with Office 2004, Adobe CS, Quicken 2007 and others.
They fixed it yesterday. The updated installer is not yet on Apple's downloads site, but it IS available via Software Update right now.
These security updates are important, so please run Software Update now and get the fix. If there are other items in there you don't care about (like iTunes 10.5.3) then simply uncheck their boxes and start the update.
This does not affect any other versions of OSX.