Trying to embed mozilla, can't getGREPathWithProperties

Hi all,

I'm trying to use XULRunner with JavaXPCOM to embed a mozilla
application in my java program.

I have built XULRunner on my Mac without any errors (I believe). I
created a new Java application and added MozillaInterfaces.jaar to my
classpath.

The code below is from the 'Embedding Mozilla in a Java Application
using JavaXPCOM' tutorial. As you can see it's not supposed to do
anything -- just trying out things one step at a time. Unfortunately,
a FileNotFoundException is caught when I use the line

File grePath = Mozilla.getGREPathWithProperties(range, null);

Does anyone know what I am doing wrong?

Thanks so much for any help,
Sam


Code:
--------

public MozillaTest() {
		Mozilla mozilla = Mozilla.getInstance();
		GREVersionRange[] range = new GREVersionRange[1];
		range[0] = new GREVersionRange("1.8.0", true, "1.9", false);

		try {
			File grePath = Mozilla.getGREPathWithProperties(range, null);
			System.out.println("success");
		} catch (FileNotFoundException e) {
			// this exception is thrown if greGREPathWithProperties cannot find
			// a GRE

			System.out.println("fail: FileNotFoundException");
		}
	}