MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
Sorry it is not behaving for you.
When I replicate your settings, I get an object with a total height of 53 mm.
I have revised the description to clarify that the external grip ring adds twice the wall thickness to the overall height of the object.