I am trying to install C* on Ubuntu Desktop 13.04 running on Acer 64 Bit AMD desktop.

The error/warning I get is

W: Failed to fetch http://www.apache.org/dist/incubator/cassandra/debian/dists/unstable/main/source/Sources  404  Not Found [IP: 80]

W: Failed to fetch http://www.apache.org/dist/incubator/cassandra/debian/dists/unstable/main/binary-amd64/Packages  404  Not Found [IP: 80]

W: Failed to fetch http://www.apache.org/dist/incubator/cassandra/debian/dists/unstable/main/binary-i386/Packages  404  Not Found [IP: 80]

I was following instructions at http://dustyreagan.com/installing-cassandra-on-ubuntu-linux/

I was able to install C* last week at work on Ubuntu server following the same link.

I am curious if this is indeed a missing packages case.