I am still having this problem and nothing has been done about it. I can print in all other browsers except Firefox. I think it may have begun with the last upgrade. I use a Hewlett Packard Photoshop Premium C-309g-m. I generally have it connected through Airport by Wi-Fi, but the same problem still exists with it connected through the USB port. It prints in Safari, but that is much slower than using Firefox. I do not see any fix. Things that print directly through Adobe Acrobat will print. I think they use a different driver. However, that is not very much. I think Hewlett Packard recently had an upgrade while Firefox did too. Thanks a lot. Donna

Try the reset described here:
http://kb.mozillazine.org/Problems_printing_web_pages#Reset_printer

I tried this, but it still did not work with my Hewlett Packard Photosmart 309 series printer. Is this for a Macintosh, or just a PC? I am not sure what I am doing. I sure hope an update will help the printing problem. My printer works with all other browsers except Firefox, and it is the only one that can be tweaked to print international postal labels, so I really need it.