Hi Bernd,

It's a bug.

I've just revised Guide so that "Go To... Comet" will list _all_
comets if they are On or Off. If they're shown to a particular
magnitude limit, though, then only those brighter than that magnitude
limit will be shown. That change will show up the next time I post an
update. Also, it will be possible to sort the comets by designation,
as well as by name.

-- Bill