Michael, couldn't you not allow to export meshes and save NURBS with render mesh, but ignore mesh data for opening? I would be so glad, if I could keep the layer structure during meshing. If you would implement this (it could be a hidden option in the ini file), no confusion would be caused, because meshes can't be imported/opened.
Micha
Visualisation for Designer and Architects
| http://www.simulacrum.de |