Try to download the latest Firefox 22.0 and make a test on it.
32-bit: http://archive.ubuntu.com/ubuntu/pool/main/f/firefox/firefox_22.0+build2-0ubuntu0.12.04.2_i386.deb 64-bit: http://archive.ubuntu.com/ubuntu/pool/main/f/firefox/firefox_22.0+build2-0ubuntu0.12.04.2_amd64.deb Then let us know if it worked or not.
