Hi pior, by default the DXF export will create a LINE, CIRCLE, or ARC entity in the exported DXF file if the curve in MoI matches those types.

You can disable that by a setting in moi.ini :

[DXF Export]
<...>
UseSimpleEntities=y

If you set UseSimpleEntities=n then it will write circles as polylines or splines depending on the "Write curves as:" option in the export dialog.

- Michael