Is it possible to avoid the automatic import of source packages into Karmic?

[David MENTRE]

Hello,

Following my recent questions on synchronization between Debian and
Ubuntu and my announcements on the good status of OCaml on Karmic, I
have another question to Ubuntu developers: is it possible to block
the automatic import of Debian source packages in Karmic? I can
provide the list of the source packages to block[1].

The context: as I said previously, Debian developers managing OCaml
packages are going to start the transition from OCaml 3.11.0 to
3.11.1.[2] Moreover, they have decided to decide the way packaging is
done[3]. It means uploading new source packages and rebuilding all the
OCaml packages. In short, they are going to break all the OCaml
packages in Debian Unstable. Thus, as Unstable packages are directly
imported into Karmic, it means that Karmic packages will be also
broken. Therefore my question: is it possible to stop the import of a
list of given source packages?

Sincerely yours,
david

[1] The list is made of all the packages listed at the following two URLs:
  http://bentobako.org/ubuntu-ocaml-status/raw/raw-status-binaries.txt
  http://bentobako.org/ubuntu-ocaml-status/raw/raw-status-nobindep.txt

[2] http://lists.debian.org/debian-ocaml-maint/2009/06/msg00103.html

[3] http://lists.debian.org/debian-ocaml-maint/2009/06/msg00151.html