apt-get update
Get:1 http://de.archive.ubuntu.com precise Release.gpg [198 B]
Hit http://ppa.launchpad.net precise Release.gpg
Get:2 http://de.archive.ubuntu.com precise-updates Release.gpg [198 B]
Hit http://ppa.launchpad.net precise Release
Hit http://de.archive.ubuntu.com precise-security Release.gpg
Hit http://ppa.launchpad.net precise/main Sources
Get:3 http://de.archive.ubuntu.com precise-backports Release.gpg [194 kB]
Hit http://ppa.launchpad.net precise/main i386 Packages
Get:4 http://de.archive.ubuntu.com precise Release [53.0 kB]
Hit http://ppa.launchpad.net precise/main TranslationIndex
Ign http://de.archive.ubuntu.com precise Release
Hit http://ppa.launchpad.net precise/main Translation-en
Get:5 http://de.archive.ubuntu.com precise-updates Release [53.1 kB]
Ign http://de.archive.ubuntu.com precise-updates Release
Get:6 http://de.archive.ubuntu.com precise-security Release [1,274 kB]
Ign http://de.archive.ubuntu.com precise-security Release
Get:7 http://de.archive.ubuntu.com precise-backports Release [8,431 B]
Ign http://de.archive.ubuntu.com precise-backports Release
W: GPG error: http://de.archive.ubuntu.com precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://de.archive.ubuntu.com precise-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: GPG error: http://de.archive.ubuntu.com precise-security Release: Unknown error executing gpgv
E: GPG error: http://de.archive.ubuntu.com precise-backports Release: The following signatures were invalid: NODATA 1 NODATA 2