I have attached two Firebug screenshots.
One loading this page, where SVG edit works fine.
The other from my local installation, where SVG edit fails.
It is clear that the behavior is different. Not sure why.
New: I now see one difference
this page (doc.t.o) uses the plugin: draw id="1112"
my local test uses: img type="fileId" fileId="4"
I tested using the draw plugin in my local test, but the result is the same