well you are just searching the package cache on your local machine, not the Internet. This will be the package cache as dumped on your system my the DVD image and/or from the last apt-get update that you did prior to Gutsy no longer being available at the old URL.... since that anything that triggered an apt-get update would have failed, and thus your cache stagnated, but still retained all the old meta data, which is what you are now searching...