Comment 3 for bug 346386

In one of the duplicates the following is suggested to fix the problem:

sudo cd /var/lib/apt/lists/
sudo rm archive.ubuntu.com_ubuntu_dists_jaunty_universe_binary-i386_Packages

also the same for all packages filled with HTLM from the modem
when finished with it, just update.......
hope it helps

from: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/370294/comments/1