The problem is surely in your choice of Debian repositories.
You initially posted that you had done a minimum install of Etch.
Let's continue to proceed along that path.
Use the list below as your apt source list.
Let's not use anything fancy. We need to just do the basics.
It is located at /etc/apt/sources.list.
After you have saved the new list please issue these commands:
# apt-get update
# apt-get -f install
# apt-get dist-upgrade
Edit: If you get any errors please post the output.
If none appear then issue the commands again:
# apt-get install gnome x-window-system gdm
