How do I make Firefox 5 localized?

Question

Before upgrading from Firefox 4 to Firefox 5, my interface was Dutch. After the upgrade, it suddenly became English.

Is this a bug in Firefox 5 or am I missing something?

Output of apt-cache policy firefox:

firefox:
  Installed: 5.0+build1+nobinonly-0ubuntu0.11.04.1
  Candidate: 5.0+build1+nobinonly-0ubuntu0.11.04.1
  Version table:
 *** 5.0+build1+nobinonly-0ubuntu0.11.04.1 0
        500 http://nl.archive.ubuntu.com/ubuntu/ natty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ natty-security/main amd64 Packages
        100 /var/lib/dpkg/status
     4.0+nobinonly-0ubuntu3 0
        500 http://nl.archive.ubuntu.com/ubuntu/ natty/main amd64 PackagesI u

I upgraded from 4.0.1+build1+nobinonly-0ubuntu0.11.04.3.

Answer 1

You need to install the package

firefox-locale-$code

where code is the two-letter symbol of your language.