ПОДКЛЮЧИТЕ НОВЫЕ РЕПОЗИТОРИИ.
выдаите в терминале команды
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup
sudo gedit /etc/apt/sources.list
Замените в открывшемся sources.list всё следующими строками
____________
# Automatically generated sources.list
#
http://www.ubuntulinux.nl/source-o-matic#
# If you get errors about missing keys, lookup the key in this file
# and run these commands (replace KEY with the key number)
#
# gpg --keyserver subkeys.pgp.net --recv KEY
# gpg --export --armor KEY | sudo apt-key add -
# Ubuntu supported packages (packages, GPG key: 437D05B5)
deb
http://be.archive.ubuntu.com/ubuntu dapper main restricted
deb
http://be.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb
http://security.ubuntu.com/ubuntu dapper-security main restricted
# Ubuntu supported packages (sources, GPG key: 437D05B5)
deb-src
http://be.archive.ubuntu.com/ubuntu dapper main restricted
deb-src
http://be.archive.ubuntu.com/ubuntu dapper-updates main restricted
deb-src
http://security.ubuntu.com/ubuntu dapper-security main restricted
# Ubuntu community supported packages (packages, GPG key: 437D05B5)
deb
http://be.archive.ubuntu.com/ubuntu dapper universe multiverse
deb
http://be.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb
http://security.ubuntu.com/ubuntu dapper-security universe multiverse
# Ubuntu community supported packages (sources, GPG key: 437D05B5)
deb-src
http://be.archive.ubuntu.com/ubuntu dapper universe multiverse
deb-src
http://be.archive.ubuntu.com/ubuntu dapper-updates universe multiverse
deb-src
http://security.ubuntu.com/ubuntu dapper-security universe multiverse
________________
Сохраните редактируемый файл, подключитесь к Интернет.
И выдайте в терминале команду sudo apt-get update