If you want feedback on an SVG, be sure to upload the SVG.
One of several things could be happening...
Based on your screenshot: 1) It looks like you used a transparent stroke over your red color (GOOD) but it looks like you also used a transparent stroke over your black stroke (UNNECCESSARY). If you delete the transparent stroke over your black stroked path, I think it will work better (assuming that the black stroked path is a black stroked path and has not been converted to an outline or a filled area or something).
Does it draw the black line twice?
If that does not solve the problem, please upload the SVG.
I have a problem. I use Inkscape (Inkscape 0.91 r13725) and export my picture as svg.
It draw the black line at first. But at the bottom there is some color from the filling-color (red).
I tried with different pictures, also the the pictures from example...
Can you help me?