Software updated failed

[Tom H]

On Thu, Dec 6, 2012 at 10:32 PM, JD <jd1008 at gmail.com> wrote:
>
> This is the error message:
>
> W:GPG error: http://repo.mate-desktop.org quantal InRelease: The following
> signatures couldn't be verified because the public key is not available:
> NO_PUBKEY 68980A0EA10B4DE8,
> W:GPG error: http://packages.mate-desktop.org quantal Release: The following
> signatures couldn't be verified because the public key is not available:
> NO_PUBKEY 68980A0EA10B4DE8,
> W:Failed to fetch cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386
> (20120423)/dists/precise/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 12.04 LTS _Precise Pangolin_ - Release i386
> (20120423)/dists/precise/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.
>
> Question is why is it looking for
> cdrom://Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386
> (20120423)/dists/precise/restricted/binary-i386/Packages
>
> since I am not running 12.04, but 12.10 (Quantal).
>
> Perhaps I shouldnot have upgraded from 12.04 to 12.10 ????

Re CD:

I've never had this happen to me on Ubuntu but it's happened to me on
Debian when I've installed it without using the network and ended up
with "/etc/apt/sources.list" pointing at the CD. You just have to edit
"sources.list".

Re MATE:

I've never used MATE but if you're installing it from a third-party
repository, you have to install its gpg key with gpg, apt-key, or
add-apt-repository.