Hi Scott, Alan,

Sounds as if there are two things going on here:

Scott, I had reports with the previous version that DSOs would
vanish with MPCORB turned on. I eventually tracked the problem down
and fixed it. You should be okay if you use the current version from
the Web site. (I just posted a mini-update to it that removes the
double-DSO bug mentioned by Wouter van Reeven. It also includes
the two small fixes discussed on-list: revised time zones for
Alaska, and no odd "indicators" around UCAC-2 and CMC-14 stars.)

Alan, the problem you mention (asteroids vanishing if MPCORB
isn't in use) is described at

http://www.projectpluto.com/faq_curr.htm#missing_asteroids

Essentially, the asteroids for the present era are on disk #2.
There's a reasonably straightforward way to get at that data. However,
there are also good reasons to just go ahead and use MPCORB; details
of the pros and cons of MPCORB vs. Guide's built-in elements are
given at the above URL.

-- Bill