Hello all,

There was indeed a change in Guide: I decided that there
were so many asteroid-related features that they all ought to
move to a new Asteroid Options dialog. This is described at

http://www.projectpluto.com/update8d.htm#asteroid_options

The change was made on 2 June 2008.

However, the "Use MPCORB" option will be grayed out if
Guide can't find the MPCORB file. (This will be true even
with older versions of Guide.) You have to put mpcorb.dat
or mpcorbcr.dat in your Guide folder. Then the option won't
be grayed out.

(Actually, the function is a little more flexible than this.
Suppose you have an MPCORB file named '10oct04.dat' in the folder
c:\old_mpcorb. You can hit Alt-J and enter the text

MPCORB_PATH=c:\old_mpcorb\10oct04.dat

Alternatively, using

MPCORB_PATH=c:\old_mpcorb\

would cause Guide to look for the files 'mpcorb.dat' and
'mpcorbcr.dat' in that folder.)

-- Bill