The CNC processes the GCode from Inkscape with no errors.
Oh, so you mean that the problem with the pink circle is kind of a glitch in display? If the CNC processes the gcode correctly, do you get your expected product in the end?
For converting JPG using Trace Bitmap, I might guess that the problem might be that the paths are grouped. Maybe the gcode can't handle the groups???
For text, do you convert the text to path before? If so, that text is also a group of paths. But if the text goes directly to gcode without converting to paths, then my guess is incorrect..
Edit
I didn't get much response from my mailing list request (not even from the gcode tools author). Only that we should probaby put some info on the Inkscape website about these things
But we have the same problem with that -- no one who knows how to use them is interested in writing it down.