I never had the last version of VectorWorks, only the 2009version that couldn't handle .3dm.
Just last week I received the 2013 version that can handle Rhino .3dm files - and imports MoI without a hitch.

In the office we might have some 2011 or 2012 versions so I'll check there as well.


edit: just used the .3dm export - and it works as a treat. There were some difficulties with the .dxf import and saw the .3dm export from VectorWorks - and that finally worked.

for explanation with the .dxf problems:
I had a .dwg file using 3D splines as a way to show a terrain profile. exporting those to .dxf from acad and importing that file to MoI I always got all the profiles 2x - one as the profile and 1 projected in the top view to 1 level, but that level in the middle of the height of the terrain, so it was really hard to discern between the spline I want and the ones I don't.
In the end I imported the .dwg in VectorWorks and exported again to .3dm and it worked as I wanted it to be!