I just got off the phone... Apparently the new company that took over reservations for "The Last Supper" in Milan can only take reservations for November and after, and has no control over September/October reservations. I was told that I have to get there at 8am to see if any spots are open if I want to go in September/October...
We'll be only there for half day so we can't be there in the morning, but we'll try to get there anyway to see if we can get in. It sucks. :(