Hi Jasem and Ferran,
thank you very much for your quick replies.
if you are referring to
<code>DEBUG 902.539768 sec : OTA_SIDE: 1</code>
and
<code>DEBUG 903.696959 sec : OTA_SIDE: -1</code>
I can see it myself know, thank you for pointing this out.

I just checked the log from the lx200 10micron driver to see what the mount reports. It always reports 'E' in the #Ginfo# for pier side so this is apparently correct. You can also check that yourself, it's in the logs attached in the first post. And the single line updating the telescopes pier side in the driver is also pretty clear I think:
<code>setPierSide((toupper(Ginfo.SideOfPier) == 'E') ? INDI::Telescope::PIER_EAST : INDI::Telescope::PIER_WEST);</code>
So actually there is no possiblity that the pier side is set incorrectly from the mount driver, correct?
I just remembered something additional: This odd behavior only occured when "doing" something with the mount, particularly guiding. When we just let it sit there, with guiding deactivated and no exposure active, everything was fine. But as soon as we activated guiding or told the mount to slew a bit higher because we couldn't find a star due to the bad transparency the pier side was reported as "-1". Having a look at the piece of code in INDI::Dome I can see that the pier side is only taken from the mount if
<code>OTASideSP.s == IPS_OK</code>
If this is not the case it simply takes this information from the hour angle which is calculated from the time, the observers longitude and the right ascension of the mount which in this case would imply that the flip is already done.
So, is it possible that when guiding or slewing is happening then <code>OTASideSP.s</code> is not <code>IPS_OK</code> and therefore the calculated pier side is taken which is on the other side?

Philipp

Read More...