I am having problems with the following (in an attempt to remove hyperlinks, I have removed one of the "/" from the addresses): W: GPG error: http://archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <[email protected]> W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG B725097B3ACC3965 Launchpad lffl W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG 4874D3686E80C6B7 Launchpad PPA for Banshee Team W: GPG error: http://archive.getdeb.net jaunty-getdeb Release: The following signatures were invalid: BADSIG A8A515F046D7E7CF GetDeb Archive Automatic Signing Key <[email protected]> W: GPG error: http://badgerports.org lucid Release: The following signatures were invalid: BADSIG C90F9CB90E1FAD0C Jo Shields <[email protected]> W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures were invalid: BADSIG 976B5901365C5CA1 Launchpad PPA for transmissionbt W: Failed to fetch http://ppa.launchpad.net/dlecan/openjdk/ubuntu/dists/oneiric/main/source/Sources 404 Not Found W: Failed to fetch http://ppa.launchpad.net/dlecan/openjdk/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ppa.launchpad.net/sevenmachines/flash/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ppa.launchpad.net/sun-java-community-team/sun-java6/ubuntu/dists/oneiric/main/source/Sources 404 Not Found W: Failed to fetch http://ppa.launchpad.net/sun-java-community-team/sun-java6/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found I have tried the following solutions which were in a closed case titled "The following signatures were invalid": First of all try sudo apt-get clean sudo apt-get update && sudo apt-get upgrade Some ISPs cache the packages and errors like these are reported then. If the above commands don't work, try sudo apt-get update -o Acquire::http::No-Cache=True and again sudo apt-get update && sudo apt-get upgrade If it still doesn't work, sudo apt-get update -o Acquire::BrokenProxy=true sudo apt-get update && sudo apt-get upgrade