Hi Alexander - those are polygon file formats.

MoI works on a different kind of 3D data than that - MoI works with a kind of object called "NURBS surfaces", which are a kind of spline surface, it's kind of similar to Bezier curves if you are familiar with those in 2D illustration programs.

Polygon model data is a much different type of data than that - instead of being made up of splines, it's instead made up of a whole bunch of little planar facets.

MoI can generate polygon data by dicing up spline surfaces into polygon bits - that's why you can export to STL or OBJ format out of MoI. But it's not so easy to take already diced up little facets and try to reform smooth longer spline patches from them, so that's why you can't import polygon data into MoI.

See here for some additional description:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3880.2

But basically the model that you're trying to import has a different kind of data in it than what MoI works with at modeling time.

- Michael