W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/multiverse/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/restricted/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/universe/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/main/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/multiverse/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/restricted/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu-Studio 12.10 _Quantal Quetzal_ - Release amd64 (20121017.1)/dists/quantal/universe/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/quantal/main/binary-amd64/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/quantal/main/binary-i386/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
Edite seu sources.list com sudo nano /etc/apt/sources.list
Exclua a linha com o CD de instalação (provavelmente a primeira ou segunda linha, começa com "deb cdrom:") e a linha com o URL do PPA nela. Se essa linha não estiver lá, dê uma olhada em /etc/apt/sources.list.d/ e exclua os arquivos com o PPA do gwibber.