You should forget Demoniak3D and try
GeeXLab. GeeXLab can be seen as a super-Demoniak3D.
GeeXLab has a new 3DS loader and it should load all your models correctly.
The commercial version of GeeXLab (or Demoniak3D) is an end-user application. You can control it with some command line parameters but you can't integrate it in another app.
But there is a solution that should interest you: the
GeeXLab SDK.
GeeXLab is based on this SDK...