printing half images out of acrobat

[Guest_imported]

we have just had a few files where any images in the pdf (all tiffs) have only printed in half. there is usually a diagonal line that runs across the image, the right hand side of which tend to print fine and the left hand side of which prints blank. any idea what may have caused this? strangely enough some pdfs created using the exact same distiller settings print without any problems, even with the same images in them.