Ather (1/9/2015)
Thanks Mark for the answer.
I must say it's been a week that I haven't find a solution for this, and of course I can't use iclone 6...
I've been carefull not to import .vns files in those projects, but it never works. Also, when I directly import an .iprop file into iclone 6, it does recognize it, but doest not load the project after saving, always "failed to load the file", when there only is one prop and no .vns or animations. I've tried this with all the props of the "metro city" pack, and also all the props I've made myself, there's nothing to do.
What I'm trying to understand is if this is a problem of my computer or software or if this is a more general problem, in which case I'll have to wait for an upgrade.I had the same problem with .iprop of city dowtown Metro areas, and i fix it exporting files as fbx from 3dxchage, and import them again, finally export them as props iclone6.