Hi Ulrich,

Hmmm... the only issue I can think of would be that
by default, Guide shows unrefracted altitudes. If the
discrepancy you see is about an arcminute (varies a lot
with altitude above the horizon), then this is likely
to be the culprit.

To fix it, go into Settings... Location and click on
"Include Refraction". (In German, Einstellungen...
Beobachtungsort, and "Include Refraction"; I'm afraid
the translation isn't quite complete!)

If that doesn't fix it, then I don't really know
what the problem would be.

At present, there is no way to have alt/az shown
in degrees/minutes/seconds, instead of decimal degrees.

-- Bill