Comment 66 for bug 153980

I guess this isn't the same problem, so i'm posting a separate question as well, but when I attempt to upgrade from 7.04 to 7.10 I'm told that several links are broken, e.g.:
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/main/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.45 80], among other unfound links (see below).

When I looked at the specified link via browser it gave the same 404 message.

It doesn't seem that this could be due to something systemic on my end, but I'm new to loading Linux, so you never know. (I've used and am very comfortable with Unix in institutional settings, but new to being root.)

Here's the list of (8) complaints I get from Update Manager:

Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/main/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/restricted/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/main/source/Sources.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/restricted/source/Sources.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/universe/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/universe/source/Sources.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/multiverse/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.45 80]
Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/feisty/multiverse/source/Sources.gz 404 Not Found [IP: 91.189.88.45 80]