We are using a gif file that was input into the footer of the document using insert/picture. We did have to resize it to fit within the footer. I'm not sure if it's considered distiller or pdfwriter that we use but it's what Acrobat places in Word (so we're accessing Acrobat from the icons in the menu bar).
(We've done alot of conversions from within Word, all of which had a lot of graphics, although none in the headers/footers, and they all worked fine.)