I'm having lots of trouble converting Microsoft Word documents to PDF.
Specifically, some images look great in Microsoft Word (I've tested up
to 300%!) but look fuzzy and/or jagged in PDF format, even at 100%.
The images in question are in JPEG format.

I've tried a bunch of different ways to convert the Word documents to
PDF, including PDFCreator, OpenOffice, and Adobe Acrobat 6.  I've tried
playing with the Adobe quality settings without much luck.

Am I missing something?  Why do images look fine in JPEG format and
after they are pasted into Word, but hacked up in PDF format?  Would
starting out with a different image format in the first place somehow
make a difference?

Thanks for the advice!