Be sure you have Adobe Acrobat 5.0.5 or higher (5.0 doesn't work right
in Windows XP). If you are using the "Convert to Adobe PDF" button on
the Adobe toolbar, instead try printing to Acrobat PDFWriter (click on
File | Print | Name: Acrobat PDFWriter). Once you select PDFWriter,
click on Properties. Experiment with the Graphic Resolution setting on
the Page Setup tab, and the Image Compression setting on the Compression
Options tab, to see if you can find a combination that yields more
satisfactory output. FWIW, I use 600 dpi, JPEG Medium for color, and
CCITT Group 4 for monochrome, and I'm happy with the output quality of
graphics. Hope this helps.