I've founded it!!! And losted.

I am playing 5 families. I've founded it at the 1st slot exactly as said in this forum. When I opened the 2nd family there was the ball at the same place I left it on 1st one!!! So, again, I've played a little and lost it. Then it has appeared at the 3rd family! Funny, don't you??

But I don't know how or why the ball doesn't go to the 4th family, hehe... I think the secret is the central hall, near the collectibles drawers. Somewhere there there are a wormhole linking families. Cool!!!!!