FF 4.0 didn't work for me either, so I've already gone back to 3.6.16. It was very easy to do. I simply downloaded it from http://www.mozilla.com/en-US/firefox/all-older.html and ran it. It ran as an update and I'm back to were I was with no problems. It took about 2 minutes and I didn't need to delete version 4.0 or any other files. This may work for you, too, - but I don't know enough about these things to guarantee it.

Thanks. It worked. Just had trouble find a link to the old version.

going back to 3.6 did NOT work for me and neither did resetting printers. I'm afraid that after several years with FF, I will have to go back to IE.