Hi Lawrence,

Much may depend on what items are being shown on-screen. I'd go
into "Data Shown" and start turning things off. (Asteroids and comets
can be major culprits, if shown to a faint magnitude level or from a
location other than the Earth.)

If that fails, I'd go to Extras... Toggle User-Added Datasets. It
could be that you've some large, slow dataset displayed.

Also: you may find that if you stare closely at the screen while
it's being drawn, you'll see that (say) the stars appear almost
instantly, then there's a long pause, then the legend and other items
appear. Something like that can be a good clue as to what aspect of the
display is consuming all of the time.

-- Bill