PDFcreator makes larger PDF file than it was in Word2003

I have an ebook with about 280 pages. Ive tried printing it to PDF using PDF creator. However the origial .doc size that was 28 MB was increased in PDF to ove 40 MB. I used all sorts of compresisons. Even maximum and reduced DPI produced a 25MB file size with crappy pictures.

I've noticed there are some settings for PDF like e-book and such but nothing happens when i choose it.

To put things into perspective i've tried to export this file form openoffice to PDF. It made slight modificaitons on bullets, but nothing else that i've noticed and the size of PDF was little over 18 MB which is fine. At least it is compressed propperly.

 

So what am i doing wrong? what kind of settings should i have used to get a smaller file that could be sold as an e-book in the end?