Configuring external ORB for JDK 1.4

I have some problems configuring an external ORB in JDK 1.4. What I did
was putting an orb.properties into C:\Program
Files\Java\j2re1.4.2_05\lib with the following contents:

org.omg.CORBA.ORBClass=com.ooc.CORBA.ORB
org.omg.CORBA.ORBSingletonClass=com.ooc.CORBA.ORBSingleton


I also put the following in the main() of my application (probably not
required if I have the above?):

props.put("org.omg.CORBA.ORBClass", "com.ooc.CORBA.ORB");
props.put("org.omg.CORBA.ORBSingletonClass",
"com.ooc.CORBA.ORBSingleton");

What else might be required?

I got it working fine for JDK 1.3. Are there different things to do for
1.4?

Any help is appreciated.

Thanks,
  Wilko