This is a really cool SVG demo, we really need to fix the regression.
Adding hyatt to CC as well, as he is most likely to know the correct way to fix the problem (i don't know enough about painting, etc to go about fixing this) The problem appears to be due to us not invalidating the original rect occupied by the SVGImageElement (and i presume any other SVGElement) and only repainting the final rect.
*** This bug has been marked as a duplicate of 16015 ***