Well the situation with FF3 printing is complicated. Whole printing algorithm was replaced when they moved onto Cairo graphical layer. It's very complicated now and uses a lot of NT GDI extensions as well as printing/postscript improvements. With the scaling emulation added into Final 2 FF3.0 was able to print, however, it was very hardware dependant since printing creates various undefined situations which some drivers don't handle, and one error stops whole printing. Plus, images can be incorrectly positioned. Plus, you can leak all your resources out while printing lot of pages. FF3.5 started using unicode print functions which weren't implemented until kex 4.5 (and they're far from perfect now). So the situation isn't improved yet and i'm not sure if/when it will.