See the two attachments.

The first is a text war - deploy it to the /deploy directory of a stock JBossAS distro. Start the server. (i tested on 4.2.3.GA)
The second attachment is the JMX console for this server with the war deployed.

JBossAS deploys MBeans for each vhost and context-path pair in this pattern (these are the MBean ObjectNames):

jboss.web:host=<hostname>,path=<context-path>,type=Manager

Look at the attached JMX console html and you will see three of them (I see this too on my box):

jboss.web:host=snert.home.bsd.de,path=/,type=Manager
jboss.web:host=snert.home.pilhuhn.de,path=/,type=Manager
jboss.web:host=localhost,path=/,type=Manager

The first two show vhosts that are only defined in the test .war. But the context root of "/" is only defined in ROOT.war. I believe there should only be one MBean here where path=/ - that being the one where host=localhost.

But with these three MBeans, this tells me that JBoss is telling us that the context-path of "/" (of which ROOT.war will be handling) is on three vhosts (the three host= values). That does not seem to be correct.

This affects Jopr because we now think there are three ROOT.war contexts - one per vhost. But two of those vhosts are only valid for the test.war

See http://jira.rhq-project.org/browse/RHQ-2404 for how this affects Jopr/RHQ.