W: GPG error: http://archive.ubuntu.com precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://packages.linuxmint.com maya Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3EE67F3D0FF405B2 E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_multiverse_binary-i386_Packages E: The package lists or status file could not be parsed or opened. E: _cache->open() failed, please report. W: GPG error: http://archive.getdeb.net precise-getdeb Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A8A515F046D7E7CF W: Failed to fetch http://packages.medibuntu.org/dists/precise/InRelease W: Failed to fetch http://packages.linuxmint.com/dists/maya/Release W: Failed to fetch http://download.tuxfamily.org/glxdock/repository/ubuntu/dists/maya/cairo-dock/binary-amd64/Packages 404 Not Found [IP: 88.191.250.171 80] W: Failed to fetch http://download.tuxfamily.org/glxdock/repository/ubuntu/dists/maya/cairo-dock/binary-i386/Packages 404 Not Found [IP: 88.191.250.171 80] W: Some index files failed to download. They have been ignored, or old ones used instead.