This is what I have done to generate DXF from V4.
1.) Plot to a HPGL file. (this will generate a catout.hpgl)
2.) on a PC convert HPGL to DXF using a converter that can be downloaded here
When I exported to iges I had the same result as when I exported to dxf.
I am creating the dxf directly from the V4.
I will try the hpgl option as rickyt suggested.
Thanks for your replies.