I've never quite seen this before, but I have an HP Deskjet 3900 series (3915 or 3951 I think) and am running WinXP Home and IE8. On any given web page, when I select "Print", the printer will print the HTML and not the actual page as humans see it. Even the "Print Preview" shows a preview of the HTML and not the page.
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Anyone?! I'm thinking of uninstalling IE8 and installing IE7 and/or Firefox to see what happens. No one else has seen anything like this before? (bump)
Solution: I installed Firefox 3.5 and the printing works fine now (printing from Firefox, that is; IE still won't cooperate). Internet Explorer needs to be shot, burned to a crisp, and shoveled over with dirt.