Problems using trunk (1.9) XULRunner/JavaXPCOM

Hi all,

Hopefully this is the right list.

I have some code that uses XULRunner/JavaXPCOM following the example here:
    
http://developer.mozilla.org/en/docs/JavaXPCOM:Embedding_Mozilla_in_a_Java_Application_using_JavaXPCOM

The code works fine on 1.8.1.3 (contrib), and the latest "official" 
release of xulrunner, but throws an exception in the trunk (1.9) version.

Here's the line of code that causes the exception:
    windowWatcher.openWindow(null, "http://www.google.com", "main", 
"resizable,centerscreen", null);

And here's the exception:
    Exception in thread "Thread-1" org.mozilla.xpcom.XPCOMException: The 
function "openWindow" returned an error condition  (0x80004005)
        at 
org.mozilla.xpcom.internal.XPCOMJavaProxy.callXPCOMMethod(Native Method)
        at 
org.mozilla.xpcom.internal.XPCOMJavaProxy.invoke(XPCOMJavaProxy.java:143)
        at $Proxy3.openWindow(Unknown Source)
       ...

Did something change in the initialization that's required to use 
JavaXPCOM?  Does anyone have openWindow working on the trunk builds?

Thanks in advance for any help.

--Chris