FULL PRODUCT VERSION :
java version "1.6.0-beta2"
Java(TM) SE Runtime Environment (build 1.6.0-beta2-b84)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b84, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
Java 5's jconsole consistently took the ObjectName property keys *in their original* order and used these as nodes in the MBean presentational tree.

Java 6 does something unpredictable and seemingly random -- at least in build 84.

This is a huge regression for those attempting to produce usable hierarchy views in Java 5!

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Attempt to view MBeans with ObjectNames as follows:

Windchill:wt.servlet.system=WebAppContext,wt.webAppContext=/PDMLinkX10
Windchill:wt.servlet.system=WebAppContext,wt.webAppContext=/PDMLinkX10,type=PropertiesManager
Windchill:wt.servlet.system=WebAppContext,wt.webAppContext=/PDMLinkX10,type=PropertiesManager,xxx=yyy
Windchill:wt.servlet.system=WebAppContext,wt.webAppContext=/PDMLinkX10,mmm=zzz
etc...

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would expect the following tree view:

Windchill
* WebAppContext
    * /PDMLinkX10
      * PropertiesManager
        * yyy
      * zzz

as in Java 5.

I realize the standard does not speak to this and that ObjectNames equality, etc, do not consider order. Practical, predictable and version-portable presentation is a must for usability, though.
ACTUAL -
The actual hiearchy is far from that above and seems to vary by ObjectName hash order rather than the original ObjectName order.

REPRODUCIBILITY :
This bug can be reproduced always.

Release Regression From : 5.0
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.