Hi Arild,
Welcome back to the fold!
Alan's suggestion to delete the asteroids from your
comet file is one pretty good way to go. Use of MPCORB
is a good idea, too; a lot of asteroids have been found
since your CDs were burned. But I'd also _strongly_
recommend that you get the current update from
http://www.projectpluto.com/update8.htm
which fixes the "double asteroid" problem, along with
several other bugs reported over the years.
-- Bill