SVG to PNG Server side - using node.js
===

I'm trying to follow this tutorial on converting a d3.js SVG Vis to a PNG server-side (using Node.js) http://eng.wealthfront.com/2011/12/converting-dynamic-svg-to-png-with.html

Link to full code: https://gist.github.com/1509145

However, I keep getting this error whenever I attempt to make a request to load my page 

    /Users/me/Node/node_modules/jsdom/lib/jsdom.js:171
        features   = JSON.parse(JSON.stringify(window.document.implementation._fea
                                                              ^
    TypeError: Cannot read property 'implementation' of undefined
        at exports.env.exports.jsdom.env.processHTML (/Users/dereklo/Node/node_modules/jsdom/lib/jsdom.js:171:59)
        at Object.exports.env.exports.jsdom.env (/Users/dereklo/Node/node_modules/jsdom/lib/jsdom.js:262:5)
        at Server.<anonymous> (/Users/dereklo/Node/Pie/pie_serv.js:26:9)
        at Server.EventEmitter.emit (events.js:91:17)
        at HTTPParser.parser.onIncoming (http.js:1785:12)
        at HTTPParser.parserOnHeadersComplete [as onHeadersComplete] (http.js:111:23)
        at Socket.socket.ondata (http.

Does anybody know why this might be? I've installed the jsdom module fine, so I don't really know what's causing these issues...thanks in advance.