This code executes perfectly in 1.2.1, but crashes is 1.5.1.  I can't see anything wrong with it

1. void setup() {
   size(500, 500);
   
   
   String xmlStr = "<?xml version=\"1.0\"?><render><name>Horizontal Bars</name></render>";
   setXMLStr(xmlStr);
   }
   
   //--------------------------------------------------------------------------------//
   public void setXMLStr(String xmlStr) {
   XMLElement xml = new XMLElement(xmlStr);
   
   // extract name
   String name = xml.getChild("name").getContent();
   
   println(name);
   

1.2.1 prints out the string "  Horizontal Bars", but 1.5.1 crashes with 

 Exception in thread "Animation Thread" java.lang.NullPointerException
at sketch_may18b.setXMLStr(sketch_may18b.java:33)
at sketch_may18b.setup(sketch_may18b.java:25)
at processing.core.PApplet.handleDraw(Unknown Source)
at processing.core.PApplet.run(Unknown Source)
at java.lang.Thread.run(Thread.java:662)

Is this a bug or has something changed in the way XML needs to be handled in 1.5.1?