Hello! Let me introduce myself to group. My name is Vladimir Kalyaev (http://kalyaev.com) one of the "gcodetools" developers. gcodetools is the Inkscape extension to add CNC functionality. It generates G-Codes from SVG drawings and aimed to be a complete CAD/CAM freeware open-source workflow.
DXF import bugs. I've discovered 2 major bugs in the latest dxf_import.py release. Both of them are incorrect last "bulget" (having curvature) segment import of LWPOLYLINE. This plugin simply throws away this segment and replaces it with a straight line. Incorrect import example (straight lines point to errorneus lines. Arcs should be there): http://kalyaev.com/2010/20100513/inkscape-direct.png The source code was modified by me to correct these errors. Now all closed polylines imports correctly to Inkscape.
Also there is another missing feature: POINT primitive import due to SVG limitation (there is no POINT at all inside SVG specification). dxf_import.py imports POINTS as two circular segments and they are totally indistinguishable from the other objects. Point is very usefull for "drilling" and e.t.c so a simple solution: import them as any object (red arrow in my version) with the "d" outline "M x,y ..." (x,y)=(pointX, pointY) and special SVG-attribute "dxfpoint":"1" to distinguish from the other objects. This behaviour turns on when new "checkmark" is enabled (dxf_import.inx)
All of these corrections and additions are tested and work fine. I offer to merge them into current Inkscape dev distribution. Everyone can take these files from launchpad.net "lp:gcodetools" branch or download today's version with the DXF,svg,png examples from the http://kalyaev.com/2010/20100601/gcodetools.v85.zip
Have a nice day!
--- Vladimir Kalyaev.