W: GPG error: http://extras.ubuntu.com precise Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG D53AE39309257C1B Launchpad PPA for Ahmad
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG 83FBA1751378B444 Launchpad PPA for LibreOffice Packaging
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG 0B4AB1A8F65A7EC1 Launchpad Pali
W: GPG error: http://id.archive.ubuntu.com precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG 2E183FA1E260F5B0 Launchpad PPA for Ubuntu Tweak Testing Team
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG C2518248EEA14886 Launchpad VLC
W: GPG error: http://id.archive.ubuntu.com precise-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: Failed to fetch http://ppa.launchpad.net/scribus/ppa/ubuntu/dists/precise/main/i18n/Translation-en  Connection failed

E: Some index files failed to download. They have been ignored, or old ones used instead.