Hello Stefan!

Well...strange thing your problem.
Maybe it's your Mac version but it's strange...

I made a simple test and the result is almost PERFECT :

1) Created a simple chamfered "8" object in Moi
2) Exported in Obj to 3DC
3) Voxelized in 3DC to 4X resolution
4) Performed a standard AUTOPO to 60K polys using ALL standard options and without any manual twiking
5) Almost perfect result!!!


As you can see...

This is the video capture of the whole test : http://take.ms/hBWZz



And these are some screen captures :


The object in Moi :





The Voxel in 3DC :





The RETOPO Obj in 3DC :





The obj imported in MeshLab :





Ciao! :)