On Mac OS Snow Leopard (10.6.x) the PDF Printer functionality is not available any more.
When you install Acrobat 9 or CS4 from your media, it will happily add a PDF Printer to the list of printers, but (haha) it does not work any more.
Adobe blaims Apple for this, but it seems that the PDF printer way was kind of legacy any way - it just happened to be used by almost everyone.
According to that same article, there is a workaround, which is comprised of a new menu option Save as Adobe PDF, in the drop down menu of the PDF button, on the printer dialogue.
Unfortunately, when I did a fresh install of Adobe Acrobat 9 or CS4, that option was not available, not in the default version, and also not after the updates.
To be precise, I installed from DVD media, and those contain Acrobat 9.0.0. As soon as it is installed, Acrobat phones home to find out there is an update to 9.3.1 and goes downloading and installing - which is good in itself, because now you have at least a non-vulnerable version (well, ehm, not YET known to be vulnerable).
I tried again, installed 9.0.0, then manually downloaded the 9.1.0 update and ran it. This added the much wanted Save as Adobe PDF menu item. From there on Acrobat will update itself to 9.3.1 again, but the option stays there.
Bottom line: the Save as Adobe PDF option ONLY gets installed when updating from 9.0.0 to 9.1.0.
Automatic updating DOES NOT work.
Pretty counter intuitive, but hey, that's what you pay for.