Check out this link:
http://makemusic.custhelp.com/app/answers/detail/a_id/1132/kw/pdf%20file%20are%20blank/r_id/101773

There is a known issues with Finale 2009 and Adobe Acrobat on Mac OS 10.5.4

I followed the directions in the link and everything works properly.  I just thought I would share!