Have you looked at the readme that came with the file? Sometimes there is more in it than just an email address to contact the person.  There might be some special instructions on how to work with the floor in  Poser.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi