Comment 17 for bug 551782

Yes, I have the same problem when try to upgrade Ubuntu 09.10 Karmic to 10.04 Lucid...Initially i get
extracting 'lucid.tar.gz'
authenticate 'lucid.tar.gz' against 'lucid.tar.gz.gpg'
WARNING: Failed to read mirror file

2100 out of 2108 packages were installed and then boom...
Then after a few minutes i get..
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/libg/libgnome-keyring/libgnome-keyring0_2.30.0-0ubuntu1_i386.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/x/xserver-xorg-input-synaptics/xserver-xorg-input-synaptics_1.2.2-1ubuntu1_i386.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/x/xterm/xterm_256-1ubuntu1_i386.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/l/language-pack-gnome-en/language-pack-gnome-en_10.04+20100327.1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/l/language-pack-gnome-en-base/language-pack-gnome-en-base_10.04+20100327.1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/l/language-pack-kde-en/language-pack-kde-en_10.04+20100327.1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/l/language-pack-kde-en-base/language-pack-kde-en-base_10.04+20100327.1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/t/tomcat6/libservlet2.5-java_6.0.24-2ubuntu1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/universe/k/kdeartwork/kdeartwork-theme-icon_4.4.2-0ubuntu1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/universe/k/kdeartwork/nuvola-icon-theme_4.4.2-0ubuntu1_all.deb 404 Not Found
Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/universe/k/kdeartwork/kde-icons-nuvola_4.4.2-0ubuntu1_all.deb 404 Not Found