I can say that I have also had the problem in Asylum. After putting the correct ingredients in the pot, I think it was a Shy, it said she was down in one of the extended hallways but I could not find her anywhere.
It's only happened the one time and the blue hair lady did turn up, so I don't know if that has to do with a quest or something.
Another thing that has happened a few times and only in Asylum: sometimes in the hallway with the lights puzzle when I try to leave, the player character disappears and it doesn't actually move back to the other hallway. I can still run around and the camera follows but I can't leave the lights puzzle hallway and my player character has completely disappeared.
The only way to get out is to close the game.
