This error happens because you did not set up the Medibuntu repositories properly, and Medibuntu's public key was not added. The instructions for doing this are at https://help.ubuntu.com/community/Medibuntu . Specifically, you need the following:
sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow- unauthenticated install medibuntu-keyring && sudo apt-get --quiet update Marking bug as invalid. ** Changed in: synaptic (Ubuntu) Status: New => Invalid -- W: Error de GPG: http://packages.medibuntu.org karmic Release Las firmas siguientes no se pudieron verificar porque su llave pública no está disponible: NO_PUBKEY 2EBC26B60C5A2783 https://bugs.launchpad.net/bugs/509949 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs