12.10 Software Center Requires installation of untrusted packages

[DBrim95]

I've been having major problems lately with the Ubuntu Software Center. Every time I try to install something, I get the message "Requires installation of untrusted packages" and gives me the options "ok" and "repair". If I click "ok", then the installation aborts and nothing happens. If I click "repair" I get the message "Failed to download repository information" with these details:

W:Failed to fetch http://security.ubuntu.com/ubuntu/di...ty/Release.gpg  Something wicked happened resolving 'security.ubuntu.com:http' (-5 - No address associated with hostname),
 W:Failed to fetch cdrom://Ubuntu 12.10 _Quantal Quetzal_ - Release amd64 (20121017.5)/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 12.10 _Quantal Quetzal_ - Release amd64 (20121017.5)/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 12.10 _Quantal Quetzal_ - Release amd64 (20121017.5)/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 12.10 _Quantal Quetzal_ - Release amd64 (20121017.5)/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
, E:Some index files failed to download. They have been ignored, or old ones used instead.

I'm running Ubuntu 12.10 64-Bit. I've tried solutions for older versions of Ubuntu without success. Anyone else having the same issue or know how to resolve this?