is your XmldDocument xd also null? Is it a valid SVG?

Try this for the SVG (I've generated from the site: (http://svg-edit.googlecode.com/svn/t...vg-editor.html):
<svg width="640" height="480" xmlns="http://www.w3.org/2000/svg">
 <!-- Created with SVG-edit - http://svg-edit.googlecode.com/ -->
 <g>
  <title>Layer 1</title>
  <text xml:space="preserve" text-anchor="middle" font-family="serif" font-size="24" id="svg_1" y="95" x="104" stroke-width="0" stroke="#000000" fill="#000000">Hello</text>
 </g>
</svg>
feanor91, I've compiled the SVG.dll with the SavePNG method. I will private message you with the DLL attached.