Try scaling down your dxf file by multipling it x .03937 (conversion to mm from inches if you are working in inches). I know I had to do this when importing dxf file or saving dxf files in adobe. Also if I remember you may need to change how your arcs / splines are defined. You can have them split into multiple sections. I believe the value needs to be set to 1 instead of 0 but cant remember the command.. I will see if I can dig that information up.