I am very new to both Inkscape and SVG, but I think I have found a little bug.  I would be happy to get the source and try to fix it, but I would like confirmation that it is, indeed a bug.  I am trying to extract objects by ID into plain SVG files with the command-line interface.  For example:

inkscape -z -i blue -j -l blue.svg drawing.sv

This extracts the object, all right, but it doesn't appear in the right place, so that the icon is blank.  For example, drawing.svg has a blue rectange (ID blue) whose dimensions are shown in the UI as height 150, width 200, x=100, y=625.  The height of the document is 1052.36220 (A4 at 90 dpi.)  When I look at drawing.svg in a text editor, there's a little rounding:

width="199.01431"
height="149.01431"
x="100.49285"
y="277.85504" 

The difference in the