Hi, Paul
Your Dxf loaded in BobCad 18 shows arc's backwards, Loaded it in TurboCad 8 shows correct, Saved it as new Dxf, Re-loaded in BobCad 18, Displays correct now.
All these Dxf's have different way's thy save info, So-many versions, The New Importer was supposted to handle many more, Guess thy Missed some.
The Dxf's have a header with Info it use's O-Well.
Try the one's bellow.
Hope this Helps, Chip