One of Many is correct - the two shapes you have in your DXF are splines and few CAM packages recognize splines.
The thing to do is open it in ACAD and save it as a R-12 DXF. I did this for you but the file is too large to post. I can E-mail it if you would like.
Doing this will take a spline and convert it to a polyline which all CAM packages will recognize and process.
I learned this trick from GER21 on this forum, by the way.
Scott
Consistency is a good thing....unless you're consistently an idiot.