Debian's package management system normally does not allow a package to remove or replace a file owned by another package; not unless it has been defined to replace that package.
apt-get for this because the woody version
aptitude may fail when new sources have been added to
Or for as long as there is not another release in that time frame. Typically only two stable releases are supported at any given time.
Release Notes for Debian GNU/Linux 3.1 (`sarge'), Mipsel$Id: release-notes.en.sgml,v 1.71 2006/09/18 13:21:10 fjp Exp $