Reading package lists... Error!
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>

W: GPG error: http://archive.canonical.com quantal Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG 0F678A01569113AE Launchpad Caffeine
W: GPG error: http://gb.archive.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://gb.archive.ubuntu.com quantal-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://toolbelt.heroku.com ./ Release: The following signatures were invalid: BADSIG C927EBE00F1B0520 Heroku Release Engineering <release@heroku.com>
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release

W: Failed to fetch http://toolbelt.heroku.com/ubuntu/./Packages  416  Requested Range Not Satisfiable

W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/gb.archive.ubuntu.com_ubuntu_dists_quantal_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.