I can't upgrade from 12.04 beta2 to 12.04 final, neither install any lens

In both cases, after adding the repos (for lens), and updating, when I try install them or to upgrade ubuntu I get a similar message:

W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems

e.g. From terminal:

sudo apt-get dist-upgrade

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/main i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/main i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/main i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/main i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/main i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry cdrom://Ubuntu 12.04 LTS Precise Pangolin - Release i386 (20120423)/ precise/restricted i386 Packages (/var/lib/apt/lists/Ubuntu%2012.04%20LTS%20%5fPrecise%20Pangolin%5f%20-%20Release%20i386%20(20120423)_dists_precise_restricted_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems

It is like if it is nothing to upgrade, but when I try to upgrade from the update manager i get the message: Failed to download repository information.
And in the details i get:

W:GPG error: h ttp://packages.medibuntu.org precise InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783, W:Failed to fetch h ttp://ppa.launchpad.net/jfi/pidgin/ubuntu/dists/precise/main/source/Sources 404 Not Found
, W:Failed to fetch h ttp://ppa.launchpad.net/jfi/pidgin/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found
, W:Failed to fetch h ttp://ppa.launchpad.net/remi.rerolle/unity-lens-tomboy/ubuntu/dists/precise/main/source/Sources 404 Not Found
, W:Failed to fetch h ttp://ppa.launchpad.net/remi.rerolle/unity-lens-tomboy/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found
, W:Failed to fetch h ttp://ppa.launchpad.net/unity-team/hud/ubuntu/dists/precise/main/source/Sources 404 Not Found
, W:Failed to fetch h ttp://ppa.launchpad.net/unity-team/hud/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found
, E:Some index files failed to download. They have been ignored, or old ones used instead.

I'd appreciate any help. Thank you!

Do the following and see if it helps:

1. sudo apt-get update




2. sudo apt-get upgrade

If the apt command does not work try aptitude just in case.

1. sudo aptitude update




2. sudo aptitude upgrade

I would also recommend commenting/removing the medibuntu ppa, or for that matter commenting/removing all PPA and just leave the default Ubuntu repositories that are officially supported by Ubuntu. That way you minimize the problems that might occurred when trying to read some PPAs (Specially the time it takes to complete updating the repositories).