When I finished the illustration above, I thought I'd just go ahead and draw the lines for the tiles using the correct vanishing points; i.e. the same ones used for the walls, just to show how it didn't look right that way. Lo and behold! It looked perfectly O.K. to me. Below is the result, with the tiles filled in to give a better idea of the appearance. I have no idea now why I changed it the first time, it was quite a while ago.Sorry if I gave anyone a bum steer by bringing all this up. I'm as confused as you are!
KIm, I'll check out that hand at cocktail hour this evening