In a Word 2010 document with a JPG header, the header prints differently than it looked in the print preview. This only happens on our new HP OfficeJet Pro 8610 printer. It prints fine on our HP LaserJet P1606dn.
On the 8610 the header occupies the same space, but it blows up the image such that only the top left 9th (estimated) of the actual image is shown. See the attachment as it shows what the printout looks like.