Crestfallen Studios

1) Turn Puzzles OFF.
2) Enter Lexus' Tomb, 12-pillar puzzle room.
3) Drain the room of water.
4) The two doors will be open, allowing you to acquire the treasures inside.
5) To get the Star Key, refill the room with water.
6) The two doors will now be closed, and you can't open them with water in the room.

The doors are open when the water is drained, but not when the water fills the room again, thus forcing you to do the puzzle.

Check.

I'm not sure if Lun's "check" means it's solved. Anyway, here's a word to confirm that I get the same bug. Great bug description btw. Changing switch 1754 to ON solved it for me.

Well, it wouldn't be fixed until Lun updates all the games again. I don't think he goes though all that every time an error is found.