I am having the same problem. My trip starts Aug 11. I have been following the same process as you, Midnight and 5:45 est. Nothing! I bet you are correct about the Starcruiser!!! I noticed that the reservations were difficult to get in the past but they were "gettable". Now, it seems there really are no openings. Sorry, I didn't have answers but wanted to confirm that I am experiencing a very similar, almost exactly the same, problem.