Font problems after 10.6.7
PostScript output causes errors in Distiller (problems in font definitions); and manipulating PDF objects can cause embedded fonts to become .... unembedded.
As I understand it, there were lots of security fixes to font handling in the update, but it seems to have caused loads of trouble.
The developers for an app I use, Imposition Wizard, have confirmed that things aren't working as they are supposed to and have filed bug reports with Apple.
However, as I do a lot of work with PostScript and PDFs, I will have to reinstall the OS to 10.6.6.
iMac 2006 2Ghz, Mac OS X (10.6.7), MacBook 2008