how to avoid some upgrades from a distrib

[Eric Delaunay <delaunay@lix.polytechnique.fr>]

Hello,

  I would avoid upgrade of few packages when I upgrade my system from a
new distribution.
Packages I should not upgrade are "base", "netscape" and few others. "base"
because I changed some rights on devices (under /dev) and I don't want to
reset them (and "base" is not required to upgrade (see package description)).
"netscape" because I don't want to upgrade it synchronously with system
upgrade (mostly because it's only an installer that require netscape tar to
be present in /tmp :( ).

Is there a way to tell dselect/dpkg to skip some installed packages during an
upgrade without removing them from distribution ? (if provided on a cdrom, it
hard to erase them ;) )
(dpkg is called from dselect passing -iGROEB options that recursively parse
distribution directories and upgrade *all* packages previously installed).

Thanks in advance.

-- 
 Eric Delaunay                 | "La guerre justifie l'existence des militaires.
 delaunay@lix.polytechnique.fr | En les supprimant." Henri Jeanson (1900-1970)