Hello,
there was an issue that I could not track down until today:
http://steamcommunity.com/app/603800/discussions/0/3223871682617346120/
I finally got Savegames from someone who was affected by this, and I could find the issue that caused this bug.
The Bug is now fixed. (I tested it a dozen times, so it should be fixed :P)
Affected Savegames do now work as expected.
The problem was hard to fix because it had nothing to do with loading/saving at all, it had to do with 2 puzzles in the game (10 upper part, 32 lower part).
Thanks to "douglas.bermingham" for the savegames.
Thats all for now.