Ok, bit by bit it seems to become more clear what might cause the problem:

Started with IvyGen, and

• made a cube in Silo, saved as obj

• the same cube went to IvyGen, "populated" with a small Ivy

• Vue imported the cube, but not the altered cube out of IvyGen - just as I would have predicted.

So I went and opened both obj's within wordpad (obj files are "simple" textfiles, after all). And - while the unaltered cube had tons of text within, the obj from IvyGen had been totally ----- EMPTY.

Not one single letter, empty file.

I think nobody can blame Vue for importing this kind of file as it does: empty file - nothing to show :).

Contacting the maker of IvyGen now to see what might be wrong there.

Evaluating the same problem with Blender now ...