Comment 5 for bug 149836

One problem is that linux-image-2.6.22-12-generic and linux-ubuntu-modules-2.6.22-12-generic packages has been disapeared from repositories, and if someone has cleaned package, he cannot install them again.
It is not possible purge it unless someone create manually a fake file /boot/System.map-2.6.22-12-generic, and create manually folder /lib/modules/2.6.22-12-generic.

Aptitude has a big failure, sometimes mark for autoremoval many packages that was installed by other package managers and uninstall without user wants do it.