I've just posted an update to the version at

http://www.projectpluto.com/new.htm

All I've done (so far) is to fix the asteroid misplacement oddity (which
was also a comet misplacement oddity, BTW), and the problem with
comet boundaries and lines not appearing on printouts in certain
projections.

Thanks to all for the bug reports. Don't be afraid to keep 'em coming.
I've made the mistake of not posting an update for a few months;
problems creep in when I do that. (Which is the main reason I've
not moved this over to the "normal" page for updates,
http://www.projectpluto.com/update8.htm , yet.)

-- Bill