This seems to be the key part in terms of opening that door:
Go back to the rotating room. Just inside the door, turn and click toward the center of the room. Turn and click forward to the center of the room three more times (4 total). Next, click between the two appropriate statues while having the far door which you wish to open behind you. You will then be able to access the far door...
Are you sure you are clicking between the correct two statues while having the far door which you wish to open behind you?
By the way, I have to go out for a while this evening, so if I am not back until tomorrow, that will be the reason.