Why does the smooth option not seem to work sometimes when dividing a mesh like this

[Susan]

I am wondering why I am not seeing these rows of polys smooth when I divide this 1mil mesh with the divide smooth option on? I thought I have been doing this before and the polys would be divided and bend or smooth like the book shape I drew, Instead each poly just divides into four and stays flat.

Thanks

Before divide

After divide with smooth on, why are the polys not bending at new edges?
as in book shaped lines drawn.

[marcus_civis]

Are you sure it’s not? It’s working fine for me.

Attachments

[Susan]

Thanks for testing that Marcus.
I did some tests with the object I was working with, It was not a solid so I thought that might be it.
But I found that If I had part or the model masked the smooth divide had no affect, so it looks like that was it.