Hi Larry, Anthony,

I did a little bit of checking around in the code, and I think
I'll be able to allow multiple instances more readily than I thought.
In fact, with a couple of lines of code removed, it appears to
work Just Fine, with a couple of caveats:

If you do certain functions in one window (changing user-added
datasets and downloading star catalog data or images, for example),
they will get reflected in the other window the next time it's updated.
Certain other functions (zooming in and out, changing limiting
magnitude, and so on) won't be reflected in the other chart.

The latter behavior is what we'd really want to have all the
time. That way, you could configure each separately and get a
totally different view.

Also, each instance will write out a 'startup.mar' file when
closed. So the last instance closed will be the one that determines
where things are when you start up Guide again.

I consider these to be minor annoyances, so I've removed the
single-instance limitation. I've got a couple of other bugs to
work on, but once things stabilize a bit, I'll post another
"in-testing" update and notify the list.

Thanks! -- Bill