Sorry to wake up this thread but i have been trying to do the same thing and having the same problem. The top layer is hidden and the bottom is fubar.
I really didnt understand all this mesh stuff, i'm using .99.72 now.
Just wondering if this prob has been fixed in this version or if i'm doing something wrong..
(btw i found some new v. of the plugin 3dbox and now the program crashes when i open a game that i maked before updating it)