Profile parts (manholes, catch basins) not showing correctly in AutoCAD C3D 2016

Since upgrading to ACAD C3D 2016, the structures in my profile view are showing skewed.

I've looked at the part properties and it all seems fine, so what has changed and how can I fix this, has anyone else noticed this problem?

I moved your thread to the Civil 3D & LDD Forum, please post Civil 3D related questions there.

Do your structures look like those in the image at http://www.theswamp.org/index.php?topic=48987.0

[i think you have to be a member there to see images also]

Not sure of the problem/fix though.