Hi Dave,

Hmmm... I just downloaded the most recent comet data from MPC, and
it looks to be just fine. Importing it to Guide caused no problems.
So I dunno what happened here. My best guess is that the file of
comet data stored in 'comets.dat' has been damaged.

I'd ask that you find that file (in your Guide folder) and e-mail
it to me. It will contain some information that may help me puzzle out
a cause of the problem.

_After_ you've done this, I'd suggest that you download

http://www.projectpluto.com/comets.dat

and use this to replace the 'comets.dat' in your Guide folder. This
will eliminate the (presumably) damaged file, and will also bring you
up to date.

-- Bill