For a long time I had an ongoing problem optimizing PDFs in CS3 (I believe the problem occurs with CS2 and possibly other versions too). After a file had been optimized it wouldn’t display or print properly from Apple Preview. Elements of the PDF would either be missing or only partially displayed. I found documentation of the bug online but in each case the person said there was no known workaround.
SXSW Update
A collection of links, applications (Textmate), presentations (Microformats), and photos (Flickr stream) from the last few days at SXSW 2006. This is a very tiny list — there just are not enough hours in the day for more, but everything on the list is worth checking out.