Good Morning,
Concerning of this presumed bug, I would inform you that Cubase 7.0.6 as well as its previous versions can correctly create score file by pdf format.
Cubase 7 make use of “PDF Creator” plug-in as “engine” for creating score pdf file format on Windows Operating Systems. The PDF Creator software is an open source application which allows of choosing some different pdf resolutions.
On Mac OS X, the PDF codec is already installed instead by default; when Cubase 7 prints a virtual score file by pdf format, it is not possible to change its resolution. Unfortunately this is a Mac OS X’s issue and it does not depend by Steinberg’s products. This is the reason because there is a difference of weight between a score pdf file which is made on Mac OS X compare to another which is made on a Windows operating system.