Evidently for reasons of security, Adobe's postscript printer driver is now disabled in Snow Leopard. Some information about this is here: http://forums.adobe.com/thread/300660
Acrobat Distiller is also disabled.
I publish my books with Lightning Source, and they have very specific instructions for setting up the .ps prior to distiling. But in Snow Leopard these instructions cannot be followed.
The suggestion "use the popup menu and select Adobe PDF" seems not to be adequate because the very specific settings cannot be chosen.
I've got a bug in with LS on this, but... has anyone a workaround?
Michael Everson