Does the label appear in File > Print Preview, and it just won't print? <br /> Do you have the correct size "paper" selected thru Properties for that printer when viewed thru Firefox? <br /> See if anything here helps: <br /> http://kb.mozillazine.org/Problems_printing_web_pages If that doesn't help you, I don't know what else to recommend. Without being able to login to FedEx and without access to their printer, there isn't anything I can do to see what the problem with Firefox and their printer might be. IMO, FedEX should either tell you that their printer software is made to work to IE only or not. Considering that they are a worldwide company and that Firefox has like a 30% worldwide market share, they might be disappointing like 30% of their customers with vague help responses like that. Plus, IE is for Windows OS's, what are their customers running Mac OSX or Linux supposed to do if it doesn't work in Firefox?