I had a problem getting _any_ of the SVG files from OpenClipart.org to display and thought I had stumbled on to a huge problem. Much later I realised that problem only effects Adobe SVG Viewer version 1.0 and updating to Adobe SVG Viewer version 3 made the problem seem to go away.
After a lot of trial and error I was able to get the documents to display by removing the non-essential parameters from the opening <svg> tag
Sample from OpenClipart.org Balloon_01.svg:
<svg id="svg548" sodipodi:version="0.32" width="400pt" height="400pt" sodipodi:docbase="/home/nicu/svg_gal/happy/" sodipodi:docname="/home/nicu/svg_gal/happy/baloon1_01.svg" xmlns="http://www.w3.org/2000/svg" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" xmlns:xlink="http://www.w3.org/1999/xlink">
After even more trial and error I was able to narrow it down to just this line, the removal of which allows the file to display correctly: xmlns="http://www.w3.org/2000/svg"
it can also be fixed by changing it to xmlns:svg="http://www.w3.org/2000/svg"
Which looks to me more likely to be strictly valid and correct and I hope is the actual fix. Could someone please tell me if it is correct so because having gone to all the trouble of figuring out exactly what the problem was I'd like to finally submit a patch of my own to Inkscape (and then get back to poking holes in the Standard SVG).
Sincerely
Alan Horkan http://advogato.org/person/AlanHorkan/