The regression has been fixed by reverting the metadata Beta17 upgrade:
http://hudson.qa.jboss.com/hudson/view/JBoss%20AS/job/JBoss-AS-5.0.x-Test...
I wanted to try the next metadata Beta18 release, but currently the build is broken:
http://hudson.qa.jboss.com/hudson/view/JBoss%20AS/job/JBoss-AS-5.0.x/changes