@jim said:

Yeah sorry. Splines are added incorrectly as straight lines between points. I just have not figured out how to handle splines in the dxf yet.

It may help to convert the .dxf to an older version using this: http://www.opendesign.com/guestfiles/TeighaFileConverter

Hi Jim,
I let myself to modify draw_spline methods.
I used bezier curve instead of lines for drawing splines.
Curves can be edit by "su bezier" plugin
If you interested I happy to send you code.