dselect updating when Debian config changes

[Michael Talbot-Wilson <mtw@birdseye.view.net.au>]

G'day, all.

How can I prevent dselect from downloading packages that are already 
installed, merely because the Debian version has changed?

Really, it is intolerable that that happens.  It can cost a lot of money 
in download fees.

I have attepted to defeat it by general freezes, but that makes it a lot 
of work to select something when I want to upgrade.  It is made worse by 
the terrible practice of splitting up the author's source into multiple 
Debian packages.

Several weeks ago I decided that my Debian system had become totally 
unmaintainable.  That was after I had modified a lot of selections so I 
could install something, and dselect for some reason told me that if I 
went ahead it would uninstall 90% of my system.  I guess, instead of 
looking at thousands of listed packages I was doing group selections.

I have reached total lockup.

Please reply to the list, because I'm not going to ask again if no 
replies show up.  Apologies if you've recently discussed it - I've 
resubscribed to the list only to ask this question.

Regards,
Michael Talbot-Wilson