Oohh, I didn't realize it was an extension. That must be new in 0.91.
Well, I can tell you that there is some fundamental difference between circle (ellipse) and rectangle shapes in Inkscape, as you can see in the code you posted above. And in fact, rectangles are rather unique, among all kinds of objects in Inkscape.
Draw a rectangle, ellipse, spiral and a regular path with Pen or Pencil tool. Open the XML Editor and look on the left side. You can see that everything is identified as a path (even though they are shapes, and not paths on the canvas, this is how the SVG/XML code works) except for rectangles. Rectangles have the id "rect" and everything else has id "path". I've read what the reason for that is a long time ago, but I didn't understand it, and therefore, don't remember what it is.
Whether that circumstance has anything to do with your problem, I don't know. Plus, by this logic, one might think everything should work
except rectangles. But it still could be part of it.
Have you tried cutting anything else, besides circles and rectangles? I'm just curious if it follows the same pattern of the SVG/XML ids.
After you draw the circles and rectangles, have you converted those to paths (Path menu > Object to Path) before sending to Win32 VectorPrint extension? I have the impression that everything has to be a path, to be cut with these digital cutters.
If that's not it, all I could suggest would be to contact the creator of the extension. Or if you post this problem on the Inkscape's user mailing list, he will see it. I've seen him reply to the mailing list often. Or
maybe search the mailing list archives. Maybe it's been discussed there?
http://sourceforge.net/mailarchive/forum.php?forum_name=inkscape-userYou'd have to join the mailing list, to post to it. But you don't necessarily have to receive all the future mail.
http://lists.sourceforge.net/mailman/listinfo/inkscape-userI hope some of that helps