I've had this problem off and on for years when trying to print Earthlink Webmail in Firefox. I can print fine in IE and Chrome. Today I found a different solution poking around the internets and it solved my problem (for now!)

Go to Tools/Options/Content and click on the Advanced tab next to font. On the drop down menu for "Default Character Encoding" - my original setting was at Western (ISO-8859-1). I changed it to Western (windows-1252). I am unfamiliar with the different settings so I just picked another one at random. So far it has not affected other websites or printing, and it fixed the gibberish print problem in my Earthlink Webmail right away. Good luck!

-> Tap ALT key or press F10 to show the Menu Bar

-> go to View Menu -> Zoom -> click Reset -> Page Style -> select Basic Page Style

Check and tell if its working.

Unfortunately, neither solution worked.

It's printing what looks like rows of boxes with tiny numbers in them in the body of the reply.

Thanks for the suggestions, though.

UPDATE! I went back Tools/Options/Content and click on the Advanced tab next to font. On the drop down menu and I clicked on "Allow pages to choose their own fonts, instead of my selections above". (it was blank before) It seems to be working for now.

Problems printing web pages

http://kb.mozillazine.org/Problems_printing_web_pages

Check and tell if its working.