First, could you compare the display in Print Preview with the result you're getting on paper? In Print Preview, you also have access to print scaling (e.g., 100% vs. Shrink to Fit), orientation (portrait vs. landscape), and other settings. If you can't get the results you want in Preview, or if the actual printout doesn't match preview, please see the next suggestion.

Reset
After each print job, Firefox stores information about the paper size and other printer settings. Sometimes this data becomes corrupted and needs to be cleared. To do that, you can use the about:config preferences editor. Apologies for the multiple steps, but hopefully this will work on the first try.

(1) In a new tab, type or paste about:config in the url bar and press Enter. If you see a button to be careful, please click the button (and please be careful).

(2) In the Filter box, type or paste print.print and pause while Firefox filters the list. Then right-click and Reset the following:

print.print_printer

print.printer_your_printer_name.print_bgcolor -- and all other settings for the same printer

Note: the fastest way to get through this is to right-click the item with your mouse hand, then press the r key on the keyboard with your other hand.

Does that help?

This did not solve the problem....any other ideas?

Could you post a few samples illustrating the problem? If you do not have Acrobat or another PDF creation program, you can use PrimoPDF to print to PDF from any Windows application (free), or the "Print pages to Pdf" add-on for Firefox.