Casperjs issues with SVG

gistfile1.js

//==============================================================================
// Casper generated Fri Feb 15 2013 14:10:44 GMT+0100 (CET)
//==============================================================================

var x = require('casper').selectXPath;
var casper = require('casper').create();
casper.options.viewportSize = {width: 1615, height: 964};

// THIS ONE PRODUCES A BAD SCREENSHOT:
casper.start('http://raphaeljs.com/pie.html');
// THIS ONE WORKS FINE:
//casper.start('http://raphaeljs.com/github/impact.html');
// THIS ONE DOES NOT EVEN OUTPUT ANY SCREENSHOT:
//casper.start('http://raphaeljs.com/github/dots.html');

casper.wait(2000);
casper.then(function() {
    this.captureSelector("screenshot1.png", "html");
});

casper.run(function() {this.test.renderResults(true);});