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.
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.