Hi folks,

Thanks for all the comments on this; putting them together,
I got enough information to puzzle out (I think) where the bug
was, with an uninitialized variable. (I still haven't been able
to replicate the bug myself.) I'll be posting a fixed version.

Ben, the extra "horizon dip" comes about because Guide
shows that filled horizon adjusted for mean refraction plus
the dip due to altitude. (Bump your altitude a few hundred
meters, and you'll see the horizon drop still more.) The
"linear horizon" is the mathematical one that splits the
sky into two equal hemispheres.

Andrea, no idea on the distorted observatory roof display.
I just tried gnomonic projection, and it looks about as it
ever did (lots of "stretching" of objects near the edge of
large fields of view, with great circles projected as
straight lines.) Is your observatory also being shown
incorrectly in the stereographic projection? Is anything
else confused, in addition to the roof?

u2718u, thanks for the comment on the break in
compatibility with Guide 7 disks. I have not really tried
very hard to keep them compatible (and quite a few functions
in the Guide 8 software won't work with Guide 7 disks,
simply because the necessary files didn't exist back
when the Guide 7 disks were made.)

Can you define "very strange" a little? (Are the stars
shown with odd magnitudes? Some sorts of objects in
the wrong places? Does the program crash?)

-- Bill