Sorry, that is really an Adobe support issue. When you open a PDF file in a Firefox window or tab, Adobe does the printing of that file, not Firefox. Take a look at the two screenshots I uploaded with the print dialog that Adobe uses on my WinXP system. The first shows the image as in the original PDF file in Landscape. The second shows that image in Portrait; I got that change by de-selecting '''Auto-rotate and Center''' in the Page Handling section of that print dialog window. The downside to that is, that it shrunk that image. See if that works better for you. Beyond that, Adobe didn't allow me to change the paper orientation in my printer properties by using the Properties button in that print dialog window. Another way of handling that would be to save that file to your computer and open it directly with Adobe Reader. Then see if you have more control over Adobe's printing of that file.