I will have to fire up the game and experiment. I KNOW my method works, because I have done it several times, and recently re-played the entire game for purposes of a revision.
I will play this section again, following the other three walkthroughs instructions (Bert Jamin, Soren Andersen, Sunshine) to see if their methods work also. They are calling for clicking on the final (complex) set of three stones, twice in sucession.
If their method works as well as mine, well and good. The only reason an player will have trouble with this section is if they have placed the stones in their own sequence, in which case, they must choose the curtains in the sequence they themselves used for the stones, not mine or the other authors'. They might of course also be having trouble identifying the correct curtains - they are somewhat folded and distorted by the 3D effect while you are turning, making them hard to see. Can't do anything about that.
That will be ten Dramoi.