Hi Denis,

I'd check your elevation first, then go to Settings... Projection and
select Stereographic.

I suggest the first because, if you set a really high elevation, such
as 40000 km, the "elevation dip" can be -60 degrees or so. That would
cause the horizon to dip down as you suggest. (In fact, at any elevation
greater than about 350 km, you can look down and "see" the earth as a
bitmapped object, with correct perspective.)

The chart projection could conceivably be a problem. Most people, I
suspect, run Guide only in its default (stereographic) projection. Many
of the other projcections have mathematical singularities that were difficult
to deal with, and I could conceive of situations where they might cause
the horizon to go haywire.

If neither of these turns out to explain things, I'd suggest e-mailing
me the 'startup.mar' file from your Guide folder, and I'll see if I can
use it to get the same error on my machine.

-- Bill