changelogs are often not available with updates

Binary package hint: aptitude

Upgrading jaunty, but I have seen this in all releases of Ubuntu.

90% of available updates fail to retrieve a changelog when "C" is pressed. They exist, since I can read them in /usr/share/doc after installation. It is important to know what changes are made before upgrading. I know update-manager provides a link in this case. I don't propose this as a solution, though, since a typical sys admin would not want to be messing around with links2 and a launchpad link when he/she just needs a few characters plain text to describe a change.

To reproduce:

1) wait until updates are available
2) select an upgradable package
3) press "C" to retrieve changelog

4 expected) changelog displayed

5) actual, in most cases) changelog not found.