Reading package lists... Done
W: GPG error: http://www.beerorkid.com dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 31A5F97FED8A569E
W: GPG error: http://www.linux2go.dk dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A278DF5EE8BDA4E3
W: GPG error: http://xgl.compiz.info dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 31A5F97FED8A569E
W: GPG error: http://ubuntu.geole.de dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6CBDA04570FF3753
W: GPG error: http://ubuntu.cafuego.net dapper-cafuego Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 580E2519969F3F57
W: GPG error: http://thomas.enix.org dapper Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F653CB3098D3F7A7
W: Duplicate sources.list entry http://people.ubuntu.com ./ Packages (/var/lib/apt/lists/people.ubuntu.com_%7eseb128_deb_._Packages)
W: You may want to run apt-get update to correct these problems
E: Some index files failed to download, they have been ignored, or old ones used instead.