OpenMW [OSG]: at sundown the sky ingame looks like dust on the monitor

Maybe something can be done about it. I'm really happy that there is sky now! Look for the grey spots above the sun please.

OpenMW version 0.36.0 (revision 1c151f2f)

(RM-2693 from redmine: created on 2015-06-16 by Who Knows, , closed on 2015-06-19 by scrawl ., relates #2637 (closed), duplicates #2712 (closed))