Probably related to this Bug, which was fixed for Firefox 4.0 pre release versions recently (I don't know the exact date it was fixed), but hasn't yet been fixed in the 3.6.x versions. <br /> '''Font glyphs incorrectly displayed with certain printer drivers''' <br /> https://bugzilla.mozilla.org/show_bug.cgi?id=454532 <br /> ''(Please don't comment in that Bug report unless you can provide a patch to fix the problem.)'' My suggestion is to install Firefox 4.0b7 Portable Edition to your hard drive and see if that solves your problem. The Portable version will install to its' own folderset and won't affect your current installation, like an official version of 4.0b7 would. <br /> http://portableapps.com/apps/internet/firefox_portable/test