Hello to all

I am a new user working on a PC with Windows XP. I have built a (minimum) 2 level model of my house, but am having problems with the 3d view. The aerial view is fine and I can run the virtual visitor view of the ground floor, but I can't get the virtual visitor view of the upper floor. When I select display selected level on the ground floor, it works correctly and the aerial view only shows the ground floor. However, when I do the same for the top floor the whole house is still displayed and the visitor refuses to go upstairs!

I have been through all the existing posts, the user guide and the FAQs, but found nothing of help.

Can anyone help?