DC Pro on MAC creates fuzzy images when converting *.DOC to PDF. Not all images are affected. Primarily line art in PNG format. All is OK on WIN machine

DC Pro on a MAC running ElCapitan produces muddy images on some images when converting from a *.DOC document to PDF. The problem gets worse on then doing a Save As for reduced file size. Does not seem to be a problem with photo images only line art. When creating a PDF and then a reduced file size PDF on a WIN machine, all is fine for all images. What is going on? Thanks.