I don't know much about the Lite software, but if it has Autotrace, you may be better using the Export Bitmap from Inkscape, then autotracing.

Select the image, from Edit, Export Bitmap, hit the browse button on the dialogue box. Choose where to save the file and add the extension .PNG

You will need to change the file to a JPEG before using in Robo, you can do that in paint, just save as.

Autotraced files cut faster and more smoothly than DXF conversions.

ErikaP