Lines around graphics when creating PDF

When producing a PDF from EPIC 5.2 the PDF shows lines around the graphics. Sometimes a full box sometimes just one or two sides. When the PDF is printed the lines do not show (which is good) but these PDFs are also used on the web (which is bad). I cannot recreate this same scenario when inserting the same graphic in Word, or FrameMaker, or when using XSL stylesheets and Antenna House to produce the PDF. Which narrows the issue to EPIC. Any Ideas to help would be very much appreciated.

Windows 7

Version 5.2 (February 6, 2006 (MPL-2037)

Graphics are uncompressed TIFF images

Stylesheets: .fos files

Acrobat 9.0 PDF (have experimented with multiple job options - no difference inoutput.